docs: def cif(self):
          """
          https://es.wikipedia.org/wiki/C%C3%B3digo_de_identificaci%C3%B3n_fiscal
          :return: a random Spanish CIF
          """
  
          first_chr = random.choice('ABCDEFGHJNPQRSUVW')
          doi_body = str(random.randrange(0, 10000000)).zfill(7)
          cif = first_chr + doi_body
          return cif + self._calculate_control_cif(cif)