def get_group_line(self, data):
        """Get the next group-style key's line.

        :param data: the data to proceed
        :returns: the line number

        """
        idx = -1
        for key in self.groups:
            i = self.get_group_key_line(data, key)
            if (i < idx and i != -1) or idx == -1:
                idx = i
        return idx