code: function(other, evname, callback) {
      other.on(evname, callback, this);
      var a = this._listeningTo = this._listeningTo || {},
        b = a[other._cid] = other;
    }
docs: Bind event listener on an other object
  
  @param {object} object to listen to
  @param {string} name of event
  @param {function} callback
  @return {this}