public function render_graph_dimensions()
 {
     parent::render_graph_dimensions();
     $longest_sub_identifier_width = $this->text_string_width('Min: ' . $this->i['graph_max_value'] . ' / Avg: XX / Max: ' . $this->i['graph_max_value'], $this->i['identifier_size']);
     $this->i['left_start'] = max($this->i['left_start'], $longest_sub_identifier_width);
 }