presto-main/src/main/java/io/prestosql/operator/scalar/StringFunctions.java/StringFunctions/split
class StringFunctions:    @ScalarFunction
    @LiteralParameters({"x", "y"})
    @SqlType("array(varchar(x))")
    public static Block split(@SqlType("varchar(x)") Slice string, @SqlType("varchar(y)") Slice delimiter)
    {
        return split(string, delimiter, string.length() + 1);
    }