public static @NotNull Icon getClassIconOfKind(@NotNull PsiClass aClass, int classKind) {
    final boolean isAbstract = aClass.hasModifierProperty(PsiModifier.ABSTRACT);
    Icon result = BASE_ICON.get(classKind | (isAbstract ? FLAGS_ABSTRACT : 0));
    if (result == null) {
      throw new NullPointerException(
        "No icon registered for the class " + aClass + " of kind " + classKind + " (isAbstract=" + isAbstract + ")"
      );
    }
    return result;
  }
public static @NotNull Icon getClassIconOfKind(@NotNull PsiClass aClass, int classKind)