@Nullable
  private ValidationInfo validateSource() {
    if (myRepositoryRadioButton.isSelected()) {
      Url url = getRepositoryFieldUrl();
      if (url == null) {
        return new ValidationInfo(message("dialog.message.invalid.repository.location"), myRepositoryField.getTextField());
      }

      Revision revision = getRevision();
      if (!revision.isValid() || revision.isLocal()) {
        return new ValidationInfo(message("dialog.message.invalid.revision"), myRevisionPanel.getRevisionTextField());
      }

      mySource = Target.on(url, revision);
    }
    else {
      mySource = Target.on(getSourceFile(), getRevision());
    }

    return null;
  }
@Nullable
  private ValidationInfo validateSource()