presto-main/src/main/java/io/prestosql/sql/planner/optimizations/UnaliasSymbolReferences.java/Rewriter/canonicalizeJoinCriteria
class Rewriter:        private List<JoinNode.EquiJoinClause> canonicalizeJoinCriteria(List<JoinNode.EquiJoinClause> criteria)
        {
            ImmutableList.Builder<JoinNode.EquiJoinClause> builder = ImmutableList.builder();
            for (JoinNode.EquiJoinClause clause : criteria) {
                builder.add(new JoinNode.EquiJoinClause(canonicalize(clause.getLeft()), canonicalize(clause.getRight())));
            }

            return builder.build();
        }