resume method
Resumes after a pause.
If resumeCapability is omitted, it defaults to the isolate's
Isolate.pauseCapability.
If the isolate has no pause capability, nothing happens.
Even if pause has been called more than once with the same
resumeCapability, a single resume call with stop the pause.
Implementation
void resume([Capability? resumeCapability]) {
resumeCapability ??= isolate.pauseCapability;
if (resumeCapability == null) return;
isolate.resume(resumeCapability);
}