class Predicates {

  private static final Predicates INSTANCE = new Predicates();

  /**
   * Returns the singleton instance of this class.
   * @return the singleton instance of this class.
   */
  public static Predicates instance() {
    return INSTANCE;
  }

  @VisibleForTesting
  Failures failures = Failures.instance();

  @VisibleForTesting
  Predicates() {}

  /**
   * Asserts the given <code>{@link Predicate}</code> is not null.
   * @param predicate the given {@code Predicate}.
   * @throws NullPointerException if the given {@code Predicate} is {@code null}.
   */
  public void assertIsNotNull(Predicate<?> predicate) {<FILL_FUNCTION_BODY>}
}

    requireNonNull(predicate, "The predicate to evaluate should not be null");
  
<no_super_class>