original_string: protected function determineModelReferenceSource(Model $model)
      {
          $source = $this->getReferenceSource($model);
  
          // If we have no source to fall back on at all, use the model key
          if ( ! $source) {
              $source = $model->getKeyName();
          }
  
          return $source;
      }
code: protected function determineModelReferenceSource(Model $model)
      {
          $source = $this->getReferenceSource($model);
  
          // If we have no source to fall back on at all, use the model key
          if ( ! $source) {
              $source = $model->getKeyName();
          }
  
          return $source;
      }
code_tokens: protected function determineModelReferenceSource ( Model $ model ) { $ source = $ this -> getReferenceSource ( $ model ) ; // If we have no source to fall back on at all, use the model key if ( ! $ source ) { $ source = $ model -> getKeyName ( ) ; } return $ source ; }
docstring: Returns the reference source string.
  
  @param Model $model
  @return null|string
docstring_tokens: Returns the reference source string .