code: function(name, action, context) {
          if (!name || !action) {
              return;
          }
          var handlers = this.__handlers__ || (this.__handlers__={});
          if (!handlers[name]) {
              handlers[name] = [];
          }
          else {
              if (this.has(name, action)) {
                  return;
              }
          }
          var handler = new Handler(action, context || this);
          handlers[name].push(handler);
  
          return this;
      }
docs: Register event handler
  @param  {string} name
  @param  {Function} action
  @param  {Object} [context]
  @chainable