public void stop() {
        if (!mShouldSample.get()) {
            return;
        }
        mShouldSample.set(false);
        HandlerThreadFactory.getTimerThreadHandler().removeCallbacks(mRunnable);
    }
{@link AbstractSampler} sampler defines sampler work flow.
blockcanary-analyzer/src/main/java/com/github/moduth/blockcanary/AbstractSampler.java