@Override
    public Filter visitFilter(@NotNull SiddhiQLParser.FilterContext ctx) {

        Filter filter = new Filter((Expression) visit(ctx.expression()));
        populateQueryContext(filter, ctx);
        return filter;
    }
{@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