onDone method Null safety

void onDone (
  1. void handleDone(
      )
    )

    Replaces the done event handler of this subscription.

    The handleDone function is called when the stream closes. The value may be null, in which case no function is called.

    This method replaces the current handler set by the invocation of Stream.listen, by calling asFuture, or by a previous call to onDone.

    Implementation

    void onDone(void handleDone()?);