code: function ( type ) {
              var delegate = THIS[ this.hash ],
                  i,
                  len = delegate.activePointersLists.length,
                  list;
  
              for ( i = 0; i < len; i++ ) {
                  if ( delegate.activePointersLists[ i ].type === type ) {
                      return delegate.activePointersLists[ i ];
                  }
              }
  
              list = new $.MouseTracker.GesturePointList( type );
              delegate.activePointersLists.push( list );
              return list;
          }
docs: Returns the {@link OpenSeadragon.MouseTracker.GesturePointList|GesturePointList} for the given pointer device type,
  creating and caching a new {@link OpenSeadragon.MouseTracker.GesturePointList|GesturePointList} if one doesn't already exist for the type.
  @function
  @param {String} type - The pointer device type: "mouse", "touch", "pen", etc.
  @returns {OpenSeadragon.MouseTracker.GesturePointList}