public @NotNull Collection<String> getCommonTrackingBranches(@NotNull String remoteBranch) {
    Collection<String> trackingBranches = null;
    for (GitRepository repository : myRepositories) {
      Collection<String> tb = getTrackingBranches(repository, remoteBranch);
      if (trackingBranches == null) {
        trackingBranches = tb;
      }
      else {
        trackingBranches = ContainerUtil.intersection(trackingBranches, tb);
      }
    }
    return trackingBranches == null ? Collections.emptyList() : trackingBranches;
  }
public @NotNull Collection<String> getCommonTrackingBranches(@NotNull String remoteBranch)