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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 Parse(self, parser_mediator, file_object):
 """Parses a single file-like object. Args: parser_mediator (ParserMediator):
 a parser mediator. file_object (dvfvs.FileIO):
 a file-like object to parse. Raises: UnableToParseFile: when the file cannot be parsed. """

    if not file_object:
      raise errors.UnableToParseFile('Invalid file object')

    if self._INITIAL_FILE_OFFSET is not None:
      file_object.seek(self._INITIAL_FILE_OFFSET, os.SEEK_SET)

    parser_mediator.AppendToParserChain(self)
    try:
      self.ParseFileObject(parser_mediator, file_object)
    finally:
      parser_mediator.PopFromParserChain()