presto-main/src/main/java/io/prestosql/metadata/MetadataManager.java/MetadataManager/resolveOperator
class MetadataManager:    @Override
    public ResolvedFunction resolveOperator(OperatorType operatorType, List<? extends Type> argumentTypes)
            throws OperatorNotFoundException
    {
        return functions.resolveOperator(operatorType, argumentTypes);
    }