*
   * @param reference an object reference
   * @return the non-null reference that was validated
   * @throws NullPointerException if {@code reference} is null
   * @see Verify#verifyNotNull Verify.verifyNotNull()
   */
  @CanIgnoreReturnValue
  public static <T> T checkNotNull(@Nullable T reference) {
    if (reference == null) {
      throw new NullPointerException();
    }
    return reference;