def insert_input(self, input_lines, source):
        self.input_lines.insert(self.line_offset + 1, '',
                                source='internal padding after '+source,
                                offset=len(input_lines))
        self.input_lines.insert(self.line_offset + 1, '',
                                source='internal padding before '+source,
                                offset=-1)
        self.input_lines.insert(self.line_offset + 2,
                                StringList(input_lines, source))