docs: function eventStart ( event, data ) {
  
              if ( data.handleNumbers.length === 1 ) {
  
                  var handle = scope_Handles[data.handleNumbers[0]];
  
                  // Ignore 'disabled' handles
                  if ( handle.hasAttribute('disabled') ) {
                      return false;
                  }
  
                  // Mark the handle as 'active' so it can be styled.
                  scope_ActiveHandle = handle.children[0];
                  addClass(scope_ActiveHandle, options.cssClasses.active);
              }
  
              // Fix #551, where a handle gets selected instead of dragged.
              event.preventDefault();
  
              // A drag should never propagate up to the 'tap' event.
              event.stopPropagation();
  
              // Attach the move and end events.
              var moveEvent = attachEvent(actions.move, document.documentElement, eventMove, {
                  startCalcPoint: event.calcPoint,
                  baseSize: baseSize(),
                  pageOffset: event.pageOffset,
                  handleNumbers: data.handleNumbers,
                  buttonsProperty: event.buttons,
                  locations: scope_Locations.slice()
              });
  
              var endEvent = attachEvent(actions.end, document.documentElement, eventEnd, {
                  handleNumbers: data.handleNumbers
              });
  
              var outEvent = attachEvent("mouseout", document.documentElement, documentLeave, {
                  handleNumbers: data.handleNumbers
              });
  
              document.documentElement.noUiListeners = moveEvent.concat(endEvent, outEvent);
  
              // Text selection isn't an issue on touch devices,
              // so adding cursor styles can be skipped.
              if ( event.cursor ) {
  
                  // Prevent the 'I' cursor and extend the range-drag cursor.
                  document.body.style.cursor = getComputedStyle(event.target).cursor;
  
                  // Mark the target with a dragging state.
                  if ( scope_Handles.length > 1 ) {
                      addClass(scope_Target, options.cssClasses.drag);
                  }
  
                  var f = function(){
                      return false;
                  };
  
                  document.body.noUiListener = f;
  
                  // Prevent text selection when dragging the handles.
                  document.body.addEventListener('selectstart', f, false);
              }
  
              data.handleNumbers.forEach(function(handleNumber){
                  fireEvent('start', handleNumber);
              });
          }