docs: function( roomID, key ) {
  
  		return this.getRoomIdForKey( key )
  		.then( function( savedRoomId ) {
  
  			if( savedRoomId == roomID ) {
  
  				delete idToKey[ roomID ];
  				delete keyToId[ key ];
  
  				keys.push( key );
  
  				return promise.resolve();
  			} else {
  
  				return promise.reject( 'roomID and roomID for key do not match' );
  			}
  		});
  	}