presto-main/src/main/java/io/prestosql/sql/planner/iterative/rule/TransformExistsApplyToCorrelatedJoin.java/TransformExistsApplyToCorrelatedJoin/TransformExistsApplyToCorrelatedJoin
class TransformExistsApplyToCorrelatedJoin:    public TransformExistsApplyToCorrelatedJoin(Metadata metadata)
    {
        requireNonNull(metadata, "metadata is null");
        this.metadata = metadata;
        countFunction = metadata.resolveFunction(COUNT, ImmutableList.of());
    }