code: @CheckReturnValue
      public FluentGenerator<T> filter(@Nonnull Predicate<T> predicate) {
          return from(new FilteringGenerator<>(delegate, checkNotNull(predicate)));
      }
docs: Returns FluentGenerator that filters values using provided {@code predicate}
  
  @param predicate to use for filtering
  @return Filtering FluentGenerator
  @see io.generators.core.FilteringGenerator