presto-main/src/main/java/io/prestosql/operator/scalar/JsonFunctions.java/JsonFunctions/castVarcharToJsonPath
class JsonFunctions:    @ScalarOperator(OperatorType.CAST)
    @SqlType(JsonPathType.NAME)
    @LiteralParameters("x")
    public static JsonPath castVarcharToJsonPath(@SqlType("varchar(x)") Slice pattern)
    {
        return new JsonPath(pattern.toStringUtf8());
    }