anchor.diff:     *
      * If [equals] throws, the data event is replaced by an error event
      * containing the thrown error. The behavior is equivalent to the
  -   * original stream emitting the error event.
  +   * original stream emitting the error event, and it doesn't change
  +   * the what the most recently emitted data event is.
      *
      * The returned stream is a broadcast stream if this stream is.
      * If a broadcast stream is listened to more than once, each subscription
  
positive.code:   /**
     * Provides at most the first [count] data events of this stream.
     *
     * Forwards all events of this stream to the returned stream
     * until [count] data events have been forwarded or this stream ends,
     * then ends the returned stream with a done event.
     *
     * If this stream produces fewer than [count] data events before it's done,
     * so will the returned stream.
  
negative.code:    * Creates a new stream with the same events as this stream.
     *
     * Whenever more than [timeLimit] passes between two events from this stream,
     * the [onTimeout] function is called, which can emit further events on
     * the returned stream.
     *
     * The countdown doesn't start until the returned stream is listened to.
     * The countdown is reset every time an event is forwarded from this stream,
  