original_string: public function groupBy() {
          $fields = func_get_args();
  
          if (is_array($fields[0])) {
              $fields = $fields[0];
          }
  
          $this->_groupBy = array_unique(array_merge($this->_groupBy, $fields));
  
          return $this;
      }
code: public function groupBy() {
          $fields = func_get_args();
  
          if (is_array($fields[0])) {
              $fields = $fields[0];
          }
  
          $this->_groupBy = array_unique(array_merge($this->_groupBy, $fields));
  
          return $this;
      }
code_tokens: public function groupBy ( ) { $ fields = func_get_args ( ) ; if ( is_array ( $ fields [ 0 ] ) ) { $ fields = $ fields [ 0 ] ; } $ this -> _groupBy = array_unique ( array_merge ( $ this -> _groupBy , $ fields ) ) ; return $ this ; }
docstring: Set what fields to group on.
  
  @return $this
docstring_tokens: Set what fields to group on .