/**
  * @param $row_id
  * @param $col_id
  * @return bool
  */
 public function mustHighlite($row_id, $col_id)
 {
     if (is_null($this->answer)) {
         return false;
     }
     $tuple = sprintf('%s:,', $row_id);
     return !(strstr($this->answer->value(), $tuple) === false);
 }
 /**
  * @param $row_id
  * @param $col_id
  * @return bool
  */
 public function isChecked($row_id, $col_id)
 {
     if (is_null($this->answer)) {
         return false;
     }
     $tuple = sprintf('%s:%s', $row_id, $col_id);
     return !(strstr($this->answer->value(), $tuple) === false);
 }