private @NotNull List<UnknownSdkLookup> collectSdkLookups(@NotNull ProgressIndicator indicator) {
    List<UnknownSdkLookup> lookups = new ArrayList<>();
    UnknownSdkResolver.EP_NAME.forEachExtensionSafe(ext -> {
      UnknownSdkLookup resolver = ext.createResolver(myProject, indicator);
      if (resolver != null) {
        lookups.add(resolver);
      }
    });
    return lookups;
  }
private @NotNull List<UnknownSdkLookup> collectSdkLookups(@NotNull ProgressIndicator indicator)