def header_rows(self):
        """
        [ [header1], [header3, header4] ]
        """
        # TO BE FIX: refactor
        header_rows = []
        headers = [col.header for col in self.columns]
        for header in headers:
            if len(header_rows) <= header.row_order:
                header_rows.append([])
            header_rows[header.row_order].append(header)
        return header_rows
def header_rows(self):
        """
        [ [header1], [header3, header4] ]
        """
        # TO BE FIX: refactor
        header_rows = []
        headers = [col.header for col in self.columns]
        for header in headers:
            if len(header_rows) <= header.row_order:
                header_rows.append([])
            header_rows[header.row_order].append(header)
        return header_rows
def header_rows ( self ) : # TO BE FIX: refactor header_rows = [ ] headers = [ col . header for col in self . columns ] for header in headers : if len ( header_rows ) <= header . row_order : header_rows . append ( [ ] ) header_rows [ header . row_order ] . append ( header ) return header_rows
[ [header1], [header3, header4] ]
[ [ header1 ] [ header3 header4 ] ]