original_string: public function groupBy($key, $tableName = null)
      {
          if (!$tableName) {
              $tableName = $this->getTableName();
          }
          $this->groupBy[] = ['key' => $key, 'tableName' => $tableName];
          return $this;
      }
code: public function groupBy($key, $tableName = null)
      {
          if (!$tableName) {
              $tableName = $this->getTableName();
          }
          $this->groupBy[] = ['key' => $key, 'tableName' => $tableName];
          return $this;
      }
code_tokens: public function groupBy ( $ key , $ tableName = null ) { if ( ! $ tableName ) { $ tableName = $ this -> getTableName ( ) ; } $ this -> groupBy [ ] = [ 'key' => $ key , 'tableName' => $ tableName ] ; return $ this ; }
docstring: Sets the group by for select queries.
  
  @param string      $key
  @param null|string $tableName
  
  @return $this
docstring_tokens: Sets the group by for select queries .