code: func DeRef(v interface{}) interface{} {
  	if v == nil {
  		return nil
  	}
  	k := reflect.TypeOf(v).Kind()
  	if k != reflect.Ptr {
  		return v
  	}
  	if reflect.ValueOf(v) == reflect.Zero(reflect.TypeOf(v)) {
  		// All zero-value pointers are nil
  		return nil
  	}
  	return reflect.ValueOf(v).Elem().Interface()
  }
docs: // DeRef returns the value pointed to by the interface if the interface is a
  // pointer and is not nil, otherwise returns nil, or the direct value if it's
  // not a pointer.