code: func (v *Value) GetString() (string, error) {
  	c := C.g_value_get_string(v.native())
  	if c == nil {
  		return "", errNilPtr
  	}
  	return C.GoString((*C.char)(c)), nil
  }
docs: // GetString is a wrapper around g_value_get_string().  GetString()
  // returns a non-nil error if g_value_get_string() returned a NULL
  // pointer to distinguish between returning a NULL pointer and returning
  // an empty string.