Jshn.sh: no object in an array?

Hey, is it not possible to add an object in an array?
For example

json_init
json_add_array "bla"
json_add_object "test"
json_add_int "testdata" "1"
json_close_object
json_close_array
json_dump

Will output { "bla": [ { "testdata": 1 } ] }, but I would assume { "bla": [ "test": { "testdata": 1 } ] }, so the key "test" of the object is missing.