static void forgetTranspiledStandardFunctions(TreeSet<S> functionSet) {
  for (File f : listFilesWithExtension(javaxCachesDir("Transpiled Standard Functions"), ".functions")) {
    if (!containsOneOf(lines(loadTextFile(f)), functionSet)) continue;
    deleteFile(replaceExtension(f, ".java"));
    deleteFile(f);
  }
}