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# Interface: UnderlyingSourcePullCallback<R\>

[internal](../modules/internal-10.md).UnderlyingSourcePullCallback

## Type parameters

| Name |
| :------ |
| `R` |

## Callable

### UnderlyingSourcePullCallback

▸ **UnderlyingSourcePullCallback**(`controller`): `void` \| [`PromiseLike`](internal-8.PromiseLike.md)<`void`\>

#### Parameters

| Name | Type |
| :------ | :------ |
| `controller` | [`ReadableStreamController`](../modules/internal-10.md#readablestreamcontroller)<`R`\> |

#### Returns

`void` \| [`PromiseLike`](internal-8.PromiseLike.md)<`void`\>

#### Defined in

docs-util/node_modules/typescript/lib/lib.dom.d.ts:26894