code: function KeyboardShortcuts( keyBindings ) {
  	if ( ! ( this instanceof KeyboardShortcuts ) ) {
  		return new KeyboardShortcuts( keyBindings );
  	}
  
  	// the last key and when it was pressed
  	this.lastKey = undefined;
  	this.lastKeyTime = undefined;
  
  	// the time limit for determining whether two keys in order represent a key sequence
  	this.timeLimit = 2000;
  
  	// save a copy of the bound last-key-pressed handler so it can be removed later
  	this.boundKeyHandler = this.handleKeyPress.bind( this );
  
  	// is the notifications panel open? If so we don't fire off key-handlers
  	this.isNotificationsOpen = false;
  
  	// bind the shortcuts if this is a browser environment
  	if ( typeof window !== 'undefined' ) {
  		keymaster.filter = ignoreDefaultAndContentEditableFilter;
  
  		this.bindShortcuts( keyBindings );
  	}
  }
docs: KeyboardShortcuts accepts an array of objects representing key-bindings and creates an EventEmitter
  which emits an event when a keyboard shortcut is triggered.
  
  Format: [ { eventName: 'eventName', keys: [ 'command', 'enter'] }, ...]
  
  (Optional): Setting the 'type' property of a key-binding to 'sequence' will cause the keyboard shortcut
  event to trigger only after the keys have been pressed in sequence.