code: def length(min=None, max=None):
      
  
      def validate(value):
          if min and len(value) < min:
              return e("{} does not have a length of at least {}", value, min)
          if max and len(value) > max:
              return e("{} does not have a length of at most {}", value, max)
      return validate
docs: Validates that a field value's length is between the bounds given to this
      validator.