code: def field2length(self, field, **kwargs):
          
          attributes = {}
  
          validators = [
              validator
              for validator in field.validators
              if (
                  hasattr(validator, "min")
                  and hasattr(validator, "max")
                  and hasattr(validator, "equal")
              )
          ]
  
          is_array = isinstance(
              field, (marshmallow.fields.Nested, marshmallow.fields.List)
          )
          min_attr = "minItems" if is_array else "minLength"
          max_attr = "maxItems" if is_array else "maxLength"
  
          for validator in validators:
              if validator.min is not None:
                  if hasattr(attributes, min_attr):
                      attributes[min_attr] = max(attributes[min_attr], validator.min)
                  else:
                      attributes[min_attr] = validator.min
              if validator.max is not None:
                  if hasattr(attributes, max_attr):
                      attributes[max_attr] = min(attributes[max_attr], validator.max)
                  else:
                      attributes[max_attr] = validator.max
  
          for validator in validators:
              if validator.equal is not None:
                  attributes[min_attr] = validator.equal
                  attributes[max_attr] = validator.equal
          return attributes
docs: Return the dictionary of OpenAPI field attributes for a set of
          :class:`Length <marshmallow.validators.Length>` validators.
  
          :param Field field: A marshmallow field.
          :rtype: dict