presto-main/src/main/java/io/prestosql/sql/planner/LocalExecutionPlanner.java/Visitor/visitFilter
class Visitor:        @Override
        public PhysicalOperation visitFilter(FilterNode node, LocalExecutionPlanContext context)
        {
            PlanNode sourceNode = node.getSource();

            Expression filterExpression = node.getPredicate();
            List<Symbol> outputSymbols = node.getOutputSymbols();

            return visitScanFilterAndProject(context, node.getId(), sourceNode, Optional.of(filterExpression), Assignments.identity(outputSymbols), outputSymbols);
        }