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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 extract(self, destination, format='csv', csv_delimiter=None, csv_header=True, compress=False):
 """Exports the table to GCS; blocks until complete. Args: destination: the destination URI(s). Can be a single URI or a list. format: the format to use for the exported data; one of 'csv', 'json', or 'avro' (default 'csv'). csv_delimiter: for CSV exports, the field delimiter to use. Defaults to ',' csv_header: for CSV exports, whether to include an initial header line. Default true. compress: whether to compress the data on export. Compression is not supported for AVRO format. Defaults to False. Returns: A Job object for the completed export Job if it was started successfully; else None. """

    job = self.extract_async(destination, format=format, csv_delimiter=csv_delimiter,
                             csv_header=csv_header, compress=compress)
    if job is not None:
      job.wait()
    return job