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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 write_metadata_by_name(self, name, metadata_key, metadata_value):
 """Write process metadata using a named identity. :param string name: The ProcessMetadataManager identity/name (e.g. 'pantsd'). :param string metadata_key: The metadata key (e.g. 'pid'). :param string metadata_value: The metadata value (e.g. '1729'). """

    self._maybe_init_metadata_dir_by_name(name)
    file_path = self._metadata_file_path(name, metadata_key)
    safe_file_dump(file_path, metadata_value)