code: def validate(self, meta, val):
          
          val = string_or_int_as_string_spec().normalise(meta, val)
          if not regexes['amazon_account_id'].match(val):
              raise BadOption("Account id must match a particular regex", got=val, should_match=regexes['amazon_account_id'].pattern)
          return val
docs: Validate an account_id