code: function getStandardizedButton( button ) {
          if ( $.Browser.vendor === $.BROWSERS.IE && $.Browser.version < 9 ) {
              // On IE 8, 0 == none, 1 == left, 2 == right, 3 == left and right, 4 == middle, 5 == left and middle, 6 == right and middle, 7 == all three
              // TODO: Support chorded (multiple) button presses on IE 8?
              if ( button === 1 ) {
                  return 0;
              } else if ( button === 2 ) {
                  return 2;
              } else if ( button === 4 ) {
                  return 1;
              } else {
                  return -1;
              }
          } else {
              return button;
          }
      }
docs: Returns a W3C DOM level 3 standard button value given an event.button property:
  -1 == none, 0 == primary/left, 1 == middle, 2 == secondary/right, 3 == X1/back, 4 == X2/forward, 5 == eraser (pen)
  @private
  @inner