code: public function setErrorCaller($caller = null)
      {
          if ($caller === null) {
              $caller = $this->utilities->getCallerInfo(1);
              $caller = array(
                  'file' => $caller['file'],
                  'line' => $caller['line'],
              );
          }
          if ($caller) {
              // groupEnd will check depth and potentially clear errorCaller
              $caller['groupDepth'] = $this->getGroupDepth();
          }
          $this->errorHandler->setErrorCaller($caller);
      }
docs: A wrapper for errorHandler->setErrorCaller
  
  @param array $caller (optional) null (default) determine automatically
  empty value (false, "", 0, array()) clear
  array manually set
  
  @return void