code: func InvalidLengthError(ctx string, target interface{}, ln, value int, min bool) error {
  	comp := "greater than or equal to"
  	if !min {
  		comp = "less than or equal to"
  	}
  	msg := fmt.Sprintf("length of %s must be %s %d but got value %#v (len=%d)", ctx, comp, value, target, ln)
  	return ErrInvalidRequest(msg, "attribute", ctx, "value", target, "len", ln, "comp", comp, "expected", value)
  }
docs: // InvalidLengthError is the error produced when the value of a parameter or payload field does
  // not match the length validation defined in the design.