[Bug] remove() method on ResourceIterator throws wrong Exception.

[bHacklv]

Hi,

remove() method on **ResourceIterator* that was constructed from calling columnAs() throws wrong Exception - IllegalStateException
Has to be UnsupportedOperationException

My code example:

try (final Result result = dbSteps().execute(MATCH_N_RETURN_N_TITLE_N_AUTHOR)) {
    assertThat(result.hasNext()).isTrue();
    try (final ResourceIterator<Object> objectResourceIterator = result.columnAs("n.title")) {
        assertThat(objectResourceIterator.hasNext()).isTrue();
        objectResourceIterator.remove(); \\ <--- throws wrong exception
     }
}

Same remove() operation if called on result.remove() throws correct UnsupportedOperationException.

This error is due to you are reconstructing ResourceIterator into Collections.emptyIterator:

private trait WrappingResourceIterator[T] extends ResourceIterator[T] {
    def remove() { Collections.emptyIterator[T]().remove() }
    def close() { self.close() }
  }

and then delegating remove() call to emptyIterator...
IllegalStateException is legit exception for empty Iterator (as of java.util.Collections.java), however my columnAs() does return results and shouldn't be reconstructed into empty rItr...