docs: function tooltips ( ) {
  
              // Tooltips are added with options.tooltips in original order.
              var tips = scope_Handles.map(addTooltip);
  
              bindEvent('update', function(values, handleNumber, unencoded) {
  
                  if ( !tips[handleNumber] ) {
                      return;
                  }
  
                  var formattedValue = values[handleNumber];
  
                  if ( options.tooltips[handleNumber] !== true ) {
                      formattedValue = options.tooltips[handleNumber].to(unencoded[handleNumber]);
                  }
  
                  tips[handleNumber].innerHTML = '<span>' + formattedValue + '</span>';
              });
          }