534 		_handlers: null,  property in gantt.$keyboardNavigation.EventHandler
536 			if (!this._handlers) this._handlers = {};
540 			return this._handlers[hash];
560 			if (!this._handlers) this._handlers = {};
566 				this._handlers[shortcuts.getHash(commands[i])] = handler;
574 				if (this._handlers[shortcuts.getHash(commands[i])]) {
575 					delete this._handlers[shortcuts.getHash(commands[i])];
586 			if (!this._handlers)
587 				this._handlers = {};
1048 			_handlers: null,
1277 			_handlers: null,
1419 			_handlers: null,