How to solve leakages?

What I am proposing is (A contains or is a Context instance):

public Name extends AsyncTask<Params, Progress, Result> {
    private WeakContext<A> a;

    public Name(A a) {
        this.a = new WeakReference<>(a);
    }
    
    protected Result doInBackground(Params... params) {
        final A a = this.a.get();
        if(a == null) return;
        //do stuff with a.
    }

    protected void onPostExecute(Result result) {
        final A a = this.a.get();
        if(a == null) return;
        //do stuff
    }
}

This would be a general template for all AsyncTasks (not a Java generalization).
What are your thoughts? (maybe cancel() in case of a being null?).

No files, tests, or entry points are named. Start by reviewing the six-comment thread and locating the AsyncTask implementations affected by the proposed WeakReference template. A clear outcome would define whether this is needed and how null contexts and cancellation should be handled.