code: function () {
              var me = this;
              if (me._readNotWriting) {
                  me._readNotWriting = false;
                  me._readWriteToOutput().then(undefined, function (reason) {
                      me._readReject(reason);
                  });
              }
          }
docs: Triggers write only if no write is in progress
  @since 0.2.3