@CheckForNull
  @Override
  public Instant forkDate(String referenceBranch, Path rootBaseDir) {
    return null;
  }
@Test
  public void forkDate_returns_null() throws SVNException {
    SvnScmProvider provider = new SvnScmProvider(config, new SvnBlameCommand(config));
    assertThat(provider.forkDate("", Paths.get(""))).isNull();
  }