using(fn) {
    if (!(fn instanceof Function)) throw new TypeError('action.on: The parameter must be a function.');
    this._cb = fn;
    this.isActive = true;
    if (this._onceActive){
      this._onceActive();
      this._onceActive=null;
    }
    return this;
  }
/**
   * Sets the function which the action should call.
   * @param {function} fn is the function which will be called when the action is triggered.
   * @returns {Action} for chaining
   */
Sets the function which the action should call.
@param {function} fn is the function which will be called when the action is triggered.
@returns {Action} for chaining
Sets the function which the action should call . @param { function } fn is the function which will be called when the action is triggered . @returns { Action } for chaining
using(fn) {
    if (!(fn instanceof Function)) throw new TypeError('action.on: The parameter must be a function.');
    this._cb = fn;
    this.isActive = true;
    if (this._onceActive){
      this._onceActive();
      this._onceActive=null;
    }
    return this;
  }
using ( fn ) { if ( ! ( fn instanceof Function ) ) throw new TypeError ( 'action.on: The parameter must be a function.' ) ; this . _cb = fn ; this . isActive = true ; if ( this . _onceActive ) { this . _onceActive ( ) ; this . _onceActive = null ; } return this ; }
Sets the function which the action should call.
Sets the function which the action should call .