def append_data(self, name, initial_content, size, readonly=False, sort="unknown"):
        if readonly:
            section_name = ".rodata"
        else:
            section_name = '.data'
        if initial_content is None:
            initial_content = b""
        initial_content = initial_content.ljust(size, b"\x00")
        data = Data(self, memory_data=None, section_name=section_name, name=name, initial_content=initial_content,
                    size=size, sort=sort
                    )
        if section_name == '.rodata':
            self.extra_rodata.append(data)
        else:
            self.extra_data.append(data)