presto-main/src/main/java/io/prestosql/sql/planner/optimizations/AddExchanges.java/Rewriter/createMapping
class Rewriter:        private <T> SetMultimap<T, T> createMapping(List<T> keys, List<T> values)
        {
            checkArgument(keys.size() == values.size(), "Inputs must have the same size");
            ImmutableSetMultimap.Builder<T, T> builder = ImmutableSetMultimap.builder();
            for (int i = 0; i < keys.size(); i++) {
                builder.put(keys.get(i), values.get(i));
            }
            return builder.build();
        }