// if keepNull is true. Otherwise, it will delete all the null value and keep the others.
func keepOrDeleteNullInObj(m map[string]interface{}, keepNull bool) (map[string]interface{}, error) {
	filteredMap := make(map[string]interface{})
	var err error
	for key, val := range m {
		switch {
		case keepNull && val == nil:
			filteredMap[key] = nil
		case val != nil: