getStepBeforeStep method
Returns the step that precedes the specified step, if there is one.
If the specified step is null
then it returns the last step.
Returns null
if step
was the first one in the sequence.
Implementation
@override
RPStep? getStepBeforeStep(RPStep? step, RPTaskResult? result) {
step?.timer?.cancel();
if (step == null) return steps.last;
int nextIndex = steps.indexOf(step) - 1;
if (nextIndex >= 0) return steps[nextIndex];
return null;
}