anchor.diff:    /**
      * Skips the first [count] data events from this stream.
      *
  +   * Returns a stream that emits the same events as this stream would
  +   * if listened to at the same time, except that the first [count]
  +   * data events are not emitted.
  +   * The returned stream is done when this stream is.
  +   *
  +   * If this stream emits fewer than [count] data events
  +   * before being done, the returned stream emits no data events.
  +   *
      * The returned stream is a broadcast stream if this stream is.
      * For a broadcast stream, the events are only counted from the time
      * the returned stream is listened to.
  
positive.code:    *
     * 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.
     *
     * The returned stream is a broadcast stream if this stream is.
     * If a broadcast stream is listened to more than once, each subscription
  
negative.code:   /**
     * Forwards data events while [test] is successful.
     *
     * Returns a stream that provides the same events as this stream
     * until [test] fails for a data event.
     * The returned stream is done when either this stream is done,
     * or when this stream first emits a data event that fails [test].
     *
     * The `test` call is considered failing if it returns a non-`true` value
     * or if it throws. If the `test` call throws, the error is emitted as the
     * last event on the returned streams.
     *
     * Stops listening to this stream after the accepted elements.
     *
     * Internally the method cancels its subscription after these elements. This
     * means that single-subscription (non-broadcast) streams are closed and
  