@Nullable
    @Override
    protected ValidationInfo doValidate() {
      if (StringUtil.isEmpty(myCurrentPropertyName)) {
        return new ValidationInfo(PropertiesBundle.message("copy.property.name.must.be.not.empty.error"));
      }
      return PropertiesUtil.containsProperty(myCurrentResourceBundle, myCurrentPropertyName)
             ? new ValidationInfo(PropertiesBundle.message("copy.property.with.name.0.already.exists.conflict", myCurrentPropertyName))
             : null;
    }
@Nullable
    @Override
    protected ValidationInfo doValidate()