code: def fetch_speeches(data_dir, range_start, range_end):
      
      speeches = SpeechesDataset()
      df = speeches.fetch(range_start, range_end)
      save_to_csv(df, data_dir, "speeches")
      return df
docs: :param data_dir: (str) directory in which the output file will be saved
      :param range_start: (str) date in the format dd/mm/yyyy
      :param range_end: (str) date in the format dd/mm/yyyy