/**
  * Returns the style options for bar labels
  */
 public function DataLabelStyle($dataset, $index, &$item)
 {
     $style = parent::DataLabelStyle($dataset, $index, $item);
     // old pie label settings can override global data_label settings
     $opts = array('font' => 'label_font', 'font_size' => 'label_font_size', 'font_weight' => 'label_font_weight', 'colour' => 'label_colour', 'back_colour' => 'label_back_colour');
     foreach ($opts as $key => $opt) {
         if (isset($this->settings[$opt])) {
             $style[$key] = $this->settings[$opt];
         }
     }
     return $style;
 }