function _getTransitionPrefix( transitionEnd ) {
  var TRANSITION_PREFIXES = {
    webkitTransitionEnd: '-webkit-transition',
    MozTransition:       '-moz-transition',
    OTransition:         '-o-transition',
    transitionend:       'transition'
  };

  return TRANSITION_PREFIXES[transitionEnd] ||
         TRANSITION_PREFIXES.transitionend;
}
/**
 * @param {string} transitionEnd The browser-prefixed transition end event.
 * @returns {string} The browser-prefixed transition event.
 */
@param {string} transitionEnd The browser-prefixed transition end event.
@returns {string} The browser-prefixed transition event.
@param { string } transitionEnd The browser - prefixed transition end event . @returns { string } The browser - prefixed transition event .
function _getTransitionPrefix( transitionEnd ) {
  var TRANSITION_PREFIXES = {
    webkitTransitionEnd: '-webkit-transition',
    MozTransition:       '-moz-transition',
    OTransition:         '-o-transition',
    transitionend:       'transition'
  };
  return TRANSITION_PREFIXES[transitionEnd] ||
         TRANSITION_PREFIXES.transitionend;
}
function _getTransitionPrefix ( transitionEnd ) { var TRANSITION_PREFIXES = { webkitTransitionEnd : '-webkit-transition' , MozTransition : '-moz-transition' , OTransition : '-o-transition' , transitionend : 'transition' } ; return TRANSITION_PREFIXES [ transitionEnd ] || TRANSITION_PREFIXES . transitionend ; }
@param {string} transitionEnd The browser-prefixed transition end event.
@param { string } transitionEnd The browser - prefixed transition end event .