@TestOnly
  public void registerFileType(@NotNull FileType type, @NotNull List<? extends FileNameMatcher> defaultAssociations, @NotNull Disposable disposable,
                               @NotNull PluginDescriptor pluginDescriptor) {
    if (!ApplicationManager.getApplication().isUnitTestMode()) throw new IllegalStateException();
    doRegisterFileType(type, defaultAssociations);
    Disposer.register(disposable, () -> doUnregisterFileType(type, pluginDescriptor));
  }
@TestOnly
  public void registerFileType(@NotNull FileType type, @NotNull List<? extends FileNameMatcher> defaultAssociations, @NotNull Disposable disposable,
                               @NotNull PluginDescriptor pluginDescriptor)