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/**
* ```ts
* import type { ArrayCursor, BatchedArrayCursor } from "arangojs/cursor";
* ```
*
* The "cursor" module provides cursor-related interfaces for TypeScript.
*
* @packageDocumentation
*/
import { LinkedList } from "x3-linkedlist";
import { Dict } from "./connection";
import { Database } from "./database";
/**
* Additional information about the cursor.
*/
export interface CursorExtras {
/**
* Warnings encountered while executing the query.
*/
warnings: {
code: number;
message: string;
}[];
/**
* Query execution plan for the executed query.
*/
plan?: any;
/**
* Additional profiling information for the executed query.
*/
profile?: any;
/**
* Additional statistics about the query execution.
*/
stats?: Dict<any>;
}
interface BatchView<T = any> {
isEmpty: boolean;
more(): Promise<void>;
shift(): T | undefined;
}
/**
* The `BatchedArrayCursor` provides a batch-wise API to an {@link ArrayCursor}.
*
* When using TypeScript, cursors can be cast to a specific item type in order
* to increase type safety.
*
* @param T - Type to use for each item. Defaults to `any`.
*
* @example
* ```ts
* const db = new Database();
* const query = aql`FOR x IN 1..5 RETURN x`;
* const cursor = await db.query(query) as ArrayCursor<number>;
* const batches = cursor.batches;
* ```
*
* @example
* ```js
* const db = new Database();
* const query = aql`FOR x IN 1..10000 RETURN x`;
* const cursor = await db.query(query, { batchSize: 10 });
* for await (const batch of cursor.batches) {
* // Process all values in a batch in parallel
* await Promise.all(batch.map(
* value => asyncProcessValue(value)
* ));
* }
* ```
*/
export declare class BatchedArrayCursor<T = any> {
protected _db: Database;
protected _batches: LinkedList<LinkedList<any>>;
protected _count?: number;
protected _extra: CursorExtras;
protected _hasMore: boolean;
protected _id: string | undefined;
protected _host?: number;
protected _allowDirtyRead?: boolean;
protected _itemsCursor: ArrayCursor<T>;
/**
* @internal
* @hidden
*/
constructor(db: Database, body: {
extra: any;
result: T[];
hasMore: boolean;
id: string;
count: number;
}, host?: number, allowDirtyRead?: boolean);
protected _more(): Promise<void>;
/**
* An {@link ArrayCursor} providing item-wise access to the cursor result set.
*
* See also {@link ArrayCursor.batches}.
*/
get items(): ArrayCursor<T>;
/**
* Additional information about the cursor.
*/
get extra(): Readonly<CursorExtras>;
/**
* Total number of documents in the query result. Only available if the
* `count` option was used.
*/
get count(): number | undefined;
/**
* Whether the cursor has any remaining batches that haven't yet been
* fetched. If set to `false`, all batches have been fetched and no
* additional requests to the server will be made when consuming any
* remaining batches from this cursor.
*/
get hasMore(): boolean;
/**
* Whether the cursor has more batches. If set to `false`, the cursor has
* already been depleted and contains no more batches.
*/
get hasNext(): boolean;
/**
* Enables use with `for await` to deplete the cursor by asynchronously
* yielding every batch in the cursor's remaining result set.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* @example
* ```js
* const cursor = await db.query(aql`
* FOR user IN users
* FILTER user.isActive
* RETURN user
* `);
* for await (const users of cursor.batches) {
* for (const user of users) {
* console.log(user.email, user.isAdmin);
* }
* }
* ```
*/
[Symbol.asyncIterator](): AsyncGenerator<T[], undefined, undefined>;
/**
* Loads all remaining batches from the server.
*
* **Warning**: This may impact memory use when working with very large
* query result sets.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 1 }
* );
* console.log(cursor.hasMore); // true
* await cursor.batches.loadAll();
* console.log(cursor.hasMore); // false
* console.log(cursor.hasNext); // true
* for await (const item of cursor) {
* console.log(item);
* // No server roundtrips necessary any more
* }
* ```
*/
loadAll(): Promise<void>;
/**
* Depletes the cursor, then returns an array containing all batches in the
* cursor's remaining result list.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* const result = await cursor.batches.all(); // [[1, 2], [3, 4], [5]]
* console.log(cursor.hasNext); // false
* ```
*/
all(): Promise<T[][]>;
/**
* Advances the cursor and returns all remaining values in the cursor's
* current batch. If the current batch has already been exhausted, fetches
* the next batch from the server and returns it, or `undefined` if the
* cursor has been depleted.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR i IN 1..10 RETURN i`,
* { batchSize: 5 }
* );
* const firstBatch = await cursor.batches.next(); // [1, 2, 3, 4, 5]
* await cursor.next(); // 6
* const lastBatch = await cursor.batches.next(); // [7, 8, 9, 10]
* console.log(cursor.hasNext); // false
* ```
*/
next(): Promise<T[] | undefined>;
/**
* Advances the cursor by applying the `callback` function to each item in
* the cursor's remaining result list until the cursor is depleted or
* `callback` returns the exact value `false`. Returns a promise that
* evalues to `true` unless the function returned `false`.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach | `Array.prototype.forEach`}.
*
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* const result = await cursor.batches.forEach((currentBatch) => {
* for (const value of currentBatch) {
* console.log(value);
* }
* });
* console.log(result) // true
* console.log(cursor.hasNext); // false
* ```
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* const result = await cursor.batches.forEach((currentBatch) => {
* for (const value of currentBatch) {
* console.log(value);
* }
* return false; // stop after the first batch
* });
* console.log(result); // false
* console.log(cursor.hasNext); // true
* ```
*/
forEach(callback: (currentBatch: T[], index: number, self: this) => false | void): Promise<boolean>;
/**
* Depletes the cursor by applying the `callback` function to each batch in
* the cursor's remaining result list. Returns an array containing the
* return values of `callback` for each batch.
*
* **Note**: This creates an array of all return values, which may impact
* memory use when working with very large query result sets. Consider using
* {@link BatchedArrayCursor.forEach}, {@link BatchedArrayCursor.reduce} or
* {@link BatchedArrayCursor.flatMap} instead.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map | `Array.prototype.map`}.
*
* @param R - Return type of the `callback` function.
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* const squares = await cursor.batches.map((currentBatch) => {
* return currentBatch.map((value) => value ** 2);
* });
* console.log(squares); // [[1, 4], [9, 16], [25]]
* console.log(cursor.hasNext); // false
* ```
*/
map<R>(callback: (currentBatch: T[], index: number, self: this) => R): Promise<R[]>;
/**
* Depletes the cursor by applying the `callback` function to each batch in
* the cursor's remaining result list. Returns an array containing the
* return values of `callback` for each batch, flattened to a depth of 1.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap | `Array.prototype.flatMap`}.
*
* @param R - Return type of the `callback` function.
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* const squares = await cursor.batches.flatMap((currentBatch) => {
* return currentBatch.map((value) => value ** 2);
* });
* console.log(squares); // [1, 1, 2, 4, 3, 9, 4, 16, 5, 25]
* console.log(cursor.hasNext); // false
* ```
*
* @example
* ```js
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 1 }
* );
* const odds = await cursor.batches.flatMap((currentBatch) => {
* if (currentBatch[0] % 2 === 0) {
* return []; // empty array flattens into nothing
* }
* return currentBatch;
* });
* console.logs(odds); // [1, 3, 5]
* ```
*/
flatMap<R>(callback: (currentBatch: T[], index: number, self: this) => R | R[]): Promise<R[]>;
/**
* Depletes the cursor by applying the `reducer` function to each batch in
* the cursor's remaining result list. Returns the return value of `reducer`
* for the last batch.
*
* **Note**: Most complex uses of the `reduce` method can be replaced with
* simpler code using {@link BatchedArrayCursor.forEach} or the `for await`
* syntax.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce | `Array.prototype.reduce`}.
*
* @param R - Return type of the `reducer` function.
* @param reducer - Function to execute on each element.
* @param initialValue - Initial value of the `accumulator` value passed to
* the `reducer` function.
*
* @example
* ```js
* function largestValue(baseline, values) {
* return Math.max(baseline, ...values);
* }
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 3 }
* );
* const result = await cursor.batches.reduce(largestValue, 0);
* console.log(result); // 5
* console.log(cursor.hasNext); // false
* const emptyResult = await cursor.batches.reduce(largestValue, 0);
* console.log(emptyResult); // 0
* ```
*
* @example
* ```js
* // BAD! NEEDLESSLY COMPLEX!
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 1 }
* );
* const result = await cursor.reduce((accumulator, currentBatch) => {
* accumulator[
* currentBatch[0] % 2 === 0 ? "even" : "odd"
* ].push(...currentBatch);
* return accumulator;
* }, { odd: [], even: [] });
* console.log(result); // { odd: [1, 3, 5], even: [2, 4] }
*
* // GOOD! MUCH SIMPLER!
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const odd = [];
* const even = [];
* for await (const item of cursor) {
* if (currentBatch[0] % 2 === 0) {
* even.push(...currentBatch);
* } else {
* odd.push(...currentBatch);
* }
* }
* console.log({ odd, even }); // { odd: [1, 3, 5], even: [2, 4] }
* ```
*/
reduce<R>(reducer: (accumulator: R, currentBatch: T[], index: number, self: this) => R, initialValue: R): Promise<R>;
/**
* Depletes the cursor by applying the `reducer` function to each batch in
* the cursor's remaining result list. Returns the return value of `reducer`
* for the last batch.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce | `Array.prototype.reduce`}.
*
* @param R - Return type of the `reducer` function.
* @param reducer - Function to execute on each element.
*
* @example
* ```js
* function largestValue(values1, values2) {
* return [Math.max(...values1, ...values2)];
* }
* const cursor = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 3 }
* );
* const result = await cursor.batches.reduce(largestValue);
* console.log(result); // [5]
* console.log(cursor.hasNext); // false
* ```
*
*/
reduce<R>(reducer: (accumulator: T[] | R, currentBatch: T[], index: number, self: this) => R): Promise<R | undefined>;
/**
* Drains the cursor and frees up associated database resources.
*
* This method has no effect if all batches have already been consumed.
*
* @example
* ```js
* const cursor1 = await db.query(aql`FOR x IN 1..5 RETURN x`);
* console.log(cursor1.hasMore); // false
* await cursor1.kill(); // no effect
*
* const cursor2 = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* console.log(cursor2.hasMore); // true
* await cursor2.kill(); // cursor is depleted
* ```
*/
kill(): Promise<void>;
}
/**
* The `ArrayCursor` type represents a cursor returned from a
* {@link Database.query}.
*
* When using TypeScript, cursors can be cast to a specific item type in order
* to increase type safety.
*
* See also {@link BatchedArrayCursor}.
*
* @param T - Type to use for each item. Defaults to `any`.
*
* @example
* ```ts
* const db = new Database();
* const query = aql`FOR x IN 1..5 RETURN x`;
* const result = await db.query(query) as ArrayCursor<number>;
* ```
*
* @example
* ```js
* const db = new Database();
* const query = aql`FOR x IN 1..10 RETURN x`;
* const cursor = await db.query(query);
* for await (const value of cursor) {
* // Process each value asynchronously
* await processValue(value);
* }
* ```
*/
export declare class ArrayCursor<T = any> {
protected _batches: BatchedArrayCursor<T>;
protected _view: BatchView<T>;
constructor(batchedCursor: BatchedArrayCursor, view: BatchView<T>);
/**
* A {@link BatchedArrayCursor} providing batch-wise access to the cursor
* result set.
*
* See also {@link BatchedArrayCursor.items}.
*/
get batches(): BatchedArrayCursor<T>;
/**
* Additional information about the cursor.
*/
get extra(): CursorExtras;
/**
* Total number of documents in the query result. Only available if the
* `count` option was used.
*/
get count(): number | undefined;
/**
* Whether the cursor has more values. If set to `false`, the cursor has
* already been depleted and contains no more items.
*/
get hasNext(): boolean;
/**
* Enables use with `for await` to deplete the cursor by asynchronously
* yielding every value in the cursor's remaining result set.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* @example
* ```js
* const cursor = await db.query(aql`
* FOR user IN users
* FILTER user.isActive
* RETURN user
* `);
* for await (const user of cursor) {
* console.log(user.email, user.isAdmin);
* }
* ```
*/
[Symbol.asyncIterator](): AsyncGenerator<T, undefined, undefined>;
/**
* Depletes the cursor, then returns an array containing all values in the
* cursor's remaining result list.
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.all(); // [1, 2, 3, 4, 5]
* console.log(cursor.hasNext); // false
* ```
*/
all(): Promise<T[]>;
/**
* Advances the cursor and returns the next value in the cursor's remaining
* result list, or `undefined` if the cursor has been depleted.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..3 RETURN x`);
* const one = await cursor.next(); // 1
* const two = await cursor.next(); // 2
* const three = await cursor.next(); // 3
* const empty = await cursor.next(); // undefined
* ```
*/
next(): Promise<T | undefined>;
/**
* Advances the cursor by applying the `callback` function to each item in
* the cursor's remaining result list until the cursor is depleted or
* `callback` returns the exact value `false`. Returns a promise that
* evalues to `true` unless the function returned `false`.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach | `Array.prototype.forEach`}.
*
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.forEach((currentValue) => {
* console.log(currentValue);
* });
* console.log(result) // true
* console.log(cursor.hasNext); // false
* ```
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.forEach((currentValue) => {
* console.log(currentValue);
* return false; // stop after the first item
* });
* console.log(result); // false
* console.log(cursor.hasNext); // true
* ```
*/
forEach(callback: (currentValue: T, index: number, self: this) => false | void): Promise<boolean>;
/**
* Depletes the cursor by applying the `callback` function to each item in
* the cursor's remaining result list. Returns an array containing the
* return values of `callback` for each item.
*
* **Note**: This creates an array of all return values, which may impact
* memory use when working with very large query result sets. Consider using
* {@link ArrayCursor.forEach}, {@link ArrayCursor.reduce} or
* {@link ArrayCursor.flatMap} instead.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map | `Array.prototype.map`}.
*
* @param R - Return type of the `callback` function.
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const squares = await cursor.map((currentValue) => {
* return currentValue ** 2;
* });
* console.log(squares); // [1, 4, 9, 16, 25]
* console.log(cursor.hasNext); // false
* ```
*/
map<R>(callback: (currentValue: T, index: number, self: this) => R): Promise<R[]>;
/**
* Depletes the cursor by applying the `callback` function to each item in
* the cursor's remaining result list. Returns an array containing the
* return values of `callback` for each item, flattened to a depth of 1.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap | `Array.prototype.flatMap`}.
*
* @param R - Return type of the `callback` function.
* @param callback - Function to execute on each element.
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const squares = await cursor.flatMap((currentValue) => {
* return [currentValue, currentValue ** 2];
* });
* console.log(squares); // [1, 1, 2, 4, 3, 9, 4, 16, 5, 25]
* console.log(cursor.hasNext); // false
* ```
*
* @example
* ```js
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const odds = await cursor.flatMap((currentValue) => {
* if (currentValue % 2 === 0) {
* return []; // empty array flattens into nothing
* }
* return currentValue; // or [currentValue]
* });
* console.logs(odds); // [1, 3, 5]
* ```
*/
flatMap<R>(callback: (currentValue: T, index: number, self: this) => R | R[]): Promise<R[]>;
/**
* Depletes the cursor by applying the `reducer` function to each item in
* the cursor's remaining result list. Returns the return value of `reducer`
* for the last item.
*
* **Note**: Most complex uses of the `reduce` method can be replaced with
* simpler code using {@link ArrayCursor.forEach} or the `for await` syntax.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce | `Array.prototype.reduce`}.
*
* @param R - Return type of the `reducer` function.
* @param reducer - Function to execute on each element.
* @param initialValue - Initial value of the `accumulator` value passed to
* the `reducer` function.
*
* @example
* ```js
* function largestOfTwo(one, two) {
* return Math.max(one, two);
* }
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.reduce(largestOfTwo, 0);
* console.log(result); // 5
* console.log(cursor.hasNext); // false
* const emptyResult = await cursor.reduce(largestOfTwo, 0);
* console.log(emptyResult); // 0
* ```
*
* @example
* ```js
* // BAD! NEEDLESSLY COMPLEX!
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.reduce((accumulator, currentValue) => {
* accumulator[currentValue % 2 === 0 ? "even" : "odd"].push(currentValue);
* return accumulator;
* }, { odd: [], even: [] });
* console.log(result); // { odd: [1, 3, 5], even: [2, 4] }
*
* // GOOD! MUCH SIMPLER!
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const odd = [];
* const even = [];
* for await (const item of cursor) {
* if (currentValue % 2 === 0) {
* even.push(currentValue);
* } else {
* odd.push(currentValue);
* }
* }
* console.log({ odd, even }); // { odd: [1, 3, 5], even: [2, 4] }
* ```
*/
reduce<R>(reducer: (accumulator: R, currentValue: T, index: number, self: this) => R, initialValue: R): Promise<R>;
/**
* Depletes the cursor by applying the `reducer` function to each item in
* the cursor's remaining result list. Returns the return value of `reducer`
* for the last item.
*
* **Note**: If the result set spans multiple batches, any remaining batches
* will only be fetched on demand. Depending on the cursor's TTL and the
* processing speed, this may result in the server discarding the cursor
* before it is fully depleted.
*
* See also:
* {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce | `Array.prototype.reduce`}.
*
* @param R - Return type of the `reducer` function.
* @param reducer - Function to execute on each element.
*
* @example
* ```js
* function largestOfTwo(one, two) {
* return Math.max(one, two);
* }
* const cursor = await db.query(aql`FOR x IN 1..5 RETURN x`);
* const result = await cursor.reduce(largestOfTwo);
* console.log(result); // 5
* console.log(cursor.hasNext); // false
* const emptyResult = await cursor.reduce(largestOfTwo);
* console.log(emptyResult); // undefined
* ```
*/
reduce<R>(reducer: (accumulator: T | R, currentValue: T, index: number, self: this) => R): Promise<R | undefined>;
/**
* Kills the cursor and frees up associated database resources.
*
* This method has no effect if all batches have already been fetched.
*
* @example
* ```js
* const cursor1 = await db.query(aql`FOR x IN 1..5 RETURN x`);
* console.log(cursor1.hasMore); // false
* await cursor1.kill(); // no effect
*
* const cursor2 = await db.query(
* aql`FOR x IN 1..5 RETURN x`,
* { batchSize: 2 }
* );
* console.log(cursor2.hasMore); // true
* await cursor2.kill(); // cursor is depleted
* ```
*/
kill(): Promise<void>;
}
export {};
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