code: @Nonnull
    public static <T> Predicate<T> predicate(@Nonnull final Function<T, Boolean> predicate) {
      return predicate::apply;
    }
docs: Turns a function that results in a boxed Boolean into a Predicate.
  
  @param predicate The function.
  @param <T>       The type of the argument of the function.
  @return The same function as a Predicate.