code: func (s *Schema) Normalize() error {
  	if s == nil {
  		return errors.New("is nil")
  	}
  	if s.Schema == nil {
  		return errors.New("has no type")
  	}
  	if enum := s.GetEnum(); enum != nil {
  		return enum.Normalize()
  	}
  	return nil
  }
docs: // Normalize will normalize the Schema, returning an error if it is invalid.