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# ReadableStream.locked

The **`locked`** read-only property of the `ReadableStream` interface returns whether or not the readable stream is locked to a reader.

A readable stream can have at most one active reader at a time, and is locked to that reader until it is released.
A reader might be obtained using `ReadableStream.getReader()` and released using the reader's `releaseLock()` method.

## Value

A `boolean` value indicating whether or not the readable stream is locked.
