code: func SetNestedStringMap(obj map[string]interface{}, value map[string]string, fields ...string) error {
  	m := make(map[string]interface{}, len(value)) // convert map[string]string into map[string]interface{}
  	for k, v := range value {
  		m[k] = v
  	}
  	return setNestedFieldNoCopy(obj, m, fields...)
  }
docs: // SetNestedStringMap sets the map[string]string value of a nested field.
  // Returns an error if value cannot be set because one of the nesting levels is not a map[string]interface{}.