pauseCapability property Null safety
Capability granting the ability to pause the isolate.
This capability is required by pause.
If the capability is
null, or if it is not the correct pause capability
of the isolate identified by controlPort,
then calls to pause will have no effect.
If the isolate is spawned in a paused state, use this capability as argument to the resume method in order to resume the paused isolate.
final Capability? pauseCapability;