@Nullable
  private DistributionType getSelectedGradleDistribution() {
    if (myGradleDistributionComboBox == null) return null;
    Object selection = myGradleDistributionComboBox.getSelectedItem();
    return selection == null ? null : ((DistributionTypeItem)selection).value;
  }
@Nullable
  private DistributionType getSelectedGradleDistribution()