@Override
    protected Object aggregateResult(final Object result, final Object nextResult) {
        if (nextResult == null) {
            return result;
        } else {
            return nextResult;
        }
    }
Override the aggregate result behavior. If the next result is {@code null}, return the current result. This is
used to handle child EOF, which is the last child of the {@code QueryList} context. If the next Result is not
{@code null}, return the next result. This is used to handle multiple queries, and return only the last query
result logic.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/language/grammar/GremlinAntlrToJava.java