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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 copy_submission_locally(self, cloud_path):
 """Copies submission from Google Cloud Storage to local directory. Args: cloud_path: path of the submission in Google Cloud Storage Returns: name of the local file where submission is copied to """

    local_path = os.path.join(self.download_dir, os.path.basename(cloud_path))
    cmd = ['gsutil', 'cp', cloud_path, local_path]
    if subprocess.call(cmd) != 0:
      logging.error('Can\'t copy submission locally')
      return None
    return local_path