def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def message_data(self):
        if self.proto_view == 0:
            return self.message.plain_bits_str
        elif self.proto_view == 1:
            return self.message.plain_hex_str
        elif self.proto_view == 2:
            return self.message.plain_ascii_str
        else:
            return None