public static void executeDiff(@Nullable Project project,
                                 @NotNull ExternalDiffSettings.ExternalTool externalTool,
                                 @NotNull List<? extends DiffContent> contents,
                                 @NotNull List<String> titles,
                                 @Nullable String windowTitle) throws IOException {
    try {
      GeneralCommandLine commandLine = createDiffCommandLine(project, externalTool, contents, titles, windowTitle);
      commandLine.createProcess();
    }
    catch (ExecutionException e) {
      throw new IOException(e);
    }
  }
public static void executeDiff(@Nullable Project project,
                                 @NotNull ExternalDiffSettings.ExternalTool externalTool,
                                 @NotNull List<? extends DiffContent> contents,
                                 @NotNull List<String> titles,
                                 @Nullable String windowTitle)