code: func (v *ValidationDefinition) HasRequiredOnly() bool {
  	if len(v.Values) > 0 {
  		return false
  	}
  	if v.Format != "" || v.Pattern != "" {
  		return false
  	}
  	if (v.Minimum != nil) || (v.Maximum != nil) || (v.MaxLength != nil) {
  		return false
  	}
  	return true
  }
docs: // HasRequiredOnly returns true if the validation only has the Required field with a non-zero value.