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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pack_metadata(self) -> List[Tuple[str, Any]]: """Packs the log fields and the invocation metadata into a new metadata The log fields are added in the new metadata with the key `LOG_FIELDS_KEY_META`. """

        metadata = [(k, v) for k, v in self._invocation_metadata.items()
                    if k != LOG_FIELDS_KEY_META]
        metadata.append((LOG_FIELDS_KEY_META, self._log_fields.dumps()))
        return metadata