Question

Returns the status of coroutine co, as a string:
"running",
if the coroutine is running (that is, it called status);
"suspended", if the coroutine is suspended in a call to yield,
or if it has not started running yet;
"normal" if the coroutine is active but not running
(that is, it has resumed another coroutine);
and "dead" if the coroutine has finished its body function,
or if it has stopped with an error.