json: unsupported type: chan string

[miss-invincible]

While replacing "encoding/json" with json-iterator, I encountered that json.Marshal used to throw an error when a map of this form was provided:

testMap["key"] = make(chan, string)
error returned: json: unsupported type: chan string

but, json-iterator does not return any such error on encountering this kind of data. json-iterator should have similar behaviour as old json.Marshal