code: def count_mnemonic(self, mnemonic, uwis=uwis, alias=None):
          
          all_mnemonics = self.get_mnemonics([mnemonic], uwis=uwis, alias=alias)
          return len(list(filter(None, utils.flatten_list(all_mnemonics))))
docs: Counts the wells that have a given curve, given the mnemonic and an
          alias dict.