presto-main/src/main/java/io/prestosql/type/InternalTypeManager.java/InternalTypeManager/resolveOperator
class InternalTypeManager:    @Override
    public MethodHandle resolveOperator(OperatorType operatorType, List<? extends Type> argumentTypes)
    {
        ResolvedFunction signature = metadata.resolveOperator(operatorType, argumentTypes);
        return metadata.getScalarFunctionImplementation(signature).getMethodHandle();
    }