kill method
Kills the current running process.
Returns true
if the signal is successfully delivered to the process.
Otherwise the signal could not be sent, usually meaning,
that the process is already dead.
Implementation
@override
bool kill([ProcessSignal signal = ProcessSignal.sigterm]) {
// Picked the current 'timestamp' of the run killed
_killedRunId = _runId;
_killedProcessSignal = signal;
return _kill();
}