Expanded json contains incrorect value

[chncaesar]

Description

Running the following code snippet to expand json {"key": "value", "key_2":"value_2"}.

SELECT '{"key": "value", "key_2":"value_2"}' AS col_1
, "hangzhou" AS city
AS table_1;
run table_1 as JsonExpandExt.`` where inputCol="col_1" AND samplingRatio="1.0" as result;

The result should be:

key	key_2	city
value	value_2	hangzhou

Actual result is:

key	key_2	city
0	value_2	hangzhou

Note that value becomes 0 in key column.