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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 gcs_dataset_info_files(dataset_dir):
 """Return paths to GCS files in the given dataset directory."""

  prefix = posixpath.join(GCS_DATASET_INFO_DIR, dataset_dir, "")
  # Filter for this dataset
  filenames = [el for el in gcs_files(prefix_filter=prefix)
               if el.startswith(prefix) and len(el) > len(prefix)]
  return filenames