docs: function getTransition(properties, duration, easing, delay) {
      // Get the CSS properties needed.
      var props = getProperties(properties);
  
      // Account for aliases (`in` => `ease-in`).
      if ($.cssEase[easing]) { easing = $.cssEase[easing]; }
  
      // Build the duration/easing/delay attributes for it.
      var attribs = '' + toMS(duration) + ' ' + easing;
      if (parseInt(delay, 10) > 0) { attribs += ' ' + toMS(delay); }
  
      // For more properties, add them this way:
      // "margin 200ms ease, padding 200ms ease, ..."
      var transitions = [];
      $.each(props, function(i, name) {
        transitions.push(name + ' ' + attribs);
      });
  
      return transitions.join(', ');
    }