presto-main/src/main/java/io/prestosql/operator/scalar/TypeOfFunction.java/TypeOfFunction/typeof
class TypeOfFunction:    @TypeParameter("T")
    @SqlType(StandardTypes.VARCHAR)
    public static Slice typeof(
            @TypeParameter("T") Type type,
            @SqlNullable @SqlType("T") Double value)
    {
        return typeof(type, (Object) value);
    }