presto-main/src/main/java/io/prestosql/sql/planner/optimizations/PredicatePushDown.java/Rewriter/extractJoinPredicate
class Rewriter:        private Expression extractJoinPredicate(JoinNode joinNode)
        {
            ImmutableList.Builder<Expression> builder = ImmutableList.builder();
            for (JoinNode.EquiJoinClause equiJoinClause : joinNode.getCriteria()) {
                builder.add(equiJoinClause.toExpression());
            }
            joinNode.getFilter().ifPresent(builder::add);
            return combineConjuncts(metadata, builder.build());
        }