docs: def generate_csv(path, out):
      """\
      Walks through the `path` and generates the CSV file `out`
      """
      def is_berlin_cable(filename):
          return 'BERLIN' in filename
      writer = UnicodeWriter(open(out, 'wb'), delimiter=';')
      writer.writerow(('Reference ID', 'Created', 'Origin', 'Subject'))
      for cable in cables_from_source(path, predicate=is_berlin_cable):
          writer.writerow((cable.reference_id, cable.created, cable.origin, titlefy(cable.subject)))