@Contract(pure = true)
  private static @Nullable PsiType getSelectorType(@NotNull PsiSwitchBlock switchBlock) {

    final PsiExpression selector = switchBlock.getExpression();
    if (selector == null) return null;

    return selector.getType();
  }
@Contract(pure = true)
  private static @Nullable PsiType getSelectorType(@NotNull PsiSwitchBlock switchBlock)