code: private void setInnerPredicate(Predicate<K, V> predicate) {
          if (predicate instanceof PagingPredicate) {
              throw new IllegalArgumentException("Nested PagingPredicate is not supported!");
          }
          this.predicate = predicate;
      }
docs: Sets an inner predicate.
  throws {@link IllegalArgumentException} if inner predicate is also {@link PagingPredicate}
  
  @param predicate the inner predicate through which results will be filtered