@Override
    public Object visitAbsent_sequence_source_chain(SiddhiQLParser.Absent_sequence_source_chainContext ctx) {
//        absent_sequence_source_chain
//        : '('absent_sequence_source_chain')' 
//        | basic_absent_pattern_source
//        | left_absent_sequence_source
//        | right_absent_sequence_source
//        ;

        StateElement stateElement;
        if (ctx.absent_sequence_source_chain() != null) {
            stateElement = (StateElement) visit(ctx.absent_sequence_source_chain());
        } else {
            stateElement = (StateElement) visit(ctx.getChild(0));
        }
        populateQueryContext(stateElement, ctx);
        return stateElement;
    }
{@inheritDoc}
<p>The default implementation returns the result of calling
{@link #visitChildren} on {@code ctx}.</p>

@param ctx
modules/siddhi-query-compiler/src/main/java/io/siddhi/query/compiler/internal/SiddhiQLBaseVisitorImpl.java