[golang]de nested map to flat

func NestedMapToFlatMap(a_map map[string]interface{}) map[string]interface{} {
	new_map := map[string]interface{}{}
	for key, val := range a_map{
		t:=reflect.TypeOf(val)
		if t.Kind() == reflect.Map{
			mapval, _ := val.(map[string]interface{})
			for i,j :=range mapval{
				new_map[i] = j
			}
		} else {
			new_map[key] = val
		}
	}
	for _, val := range new_map{
		t:=reflect.TypeOf(val)
		if t.Kind() == reflect.Map{
			new_map = NestedMapToFlatMap(new_map)
		}
	}
	return new_map
}