code: func fieldExcludes(fl FieldLevel) bool {
  	field := fl.Field()
  
  	currentField, _, ok := fl.GetStructFieldOK()
  	if !ok {
  		return true
  	}
  
  	return !strings.Contains(field.String(), currentField.String())
  }
docs: // FieldExcludes is the validation function for validating if the current field's value excludes the field specified by the param's value.