public function getColumns()
    {
        if (null === $this->columns) {
            $this->columns = array();
            $this->findColumns();
        }

        return $this->columns;
    }
public function getColumns()
    {
        if (null === $this->columns) {
            $this->columns = array();
            $this->findColumns();
        }

        return $this->columns;
    }
public function getColumns ( ) { if ( null === $ this -> columns ) { $ this -> columns = array ( ) ; $ this -> findColumns ( ) ; } return $ this -> columns ; }
Return a list of columns from list.display.

@return array
Return a list of columns from list . display .