code: def _validate_other_keys(optional, types, missing, validated, data,
                           to_validate):
      
      errors = []
      for key in to_validate:
          value = data[key]
          if key in optional:
              errors.extend(
                  _validate_optional_key(
                      key, missing, value, validated, optional))
              continue
          errors.extend(_validate_type_key(key, value, types, validated))
      return errors
docs: Validate the rest of the keys present in the data.