presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/ReorderJoins.java/MultiJoinNode/equals
class MultiJoinNode:        @Override
        public boolean equals(Object obj)
        {
            if (!(obj instanceof MultiJoinNode)) {
                return false;
            }

            MultiJoinNode other = (MultiJoinNode) obj;
            return this.sources.equals(other.sources)
                    && ImmutableSet.copyOf(extractConjuncts(this.filter)).equals(ImmutableSet.copyOf(extractConjuncts(other.filter)))
                    && this.outputSymbols.equals(other.outputSymbols)
                    && this.pushedProjectionThroughJoin == other.pushedProjectionThroughJoin;
        }