@NotNull
  protected static Set<String> getClassNames(PsiClass @NotNull [] classes) {
    if (classes.length == 0) {
      return Collections.emptySet();
    }

    Set<String> names = new HashSet<>(classes.length);
    for (PsiClass aClass : classes) {
      ContainerUtil.addIfNotNull(names, aClass.getName());
    }
    return names;
  }
@NotNull
  protected static Set<String> getClassNames(PsiClass @NotNull [] classes)