verify method
Throws if a request is unmatched or incomplete, optionally ignoring canceled work.
Implementation
void verify({bool ignoreCanceled = false}) {
final outstanding = _pending
.where((item) =>
!(ignoreCanceled && item.token.isCanceled) &&
(!item.matched || !item.completed))
.length;
if (outstanding > 0) {
throw StateError(
'$outstanding unhandled requests. Outstanding: $_outstanding');
}
}