Android Java Return Result from Async Task in Background Thread

How return a result from AsyncTask void onPostExecute() method in Java Android in Background Task? I had lost a lot days searching about it when Delegate Pattern Save My Life save my life. When had found here from StackOverFlow.

My Main Thread has a CsvUtil.getCompanies() method who need to return a List, and getCompanies() call a ReadLine class who consume a Google Sheet from Cloud.

public static final class ParseLine extends AsyncTask<String, Integer, String[]> {
        private TaskDelegate delegate;

        public ParseLine(TaskDelegate delegate) {
            this.delegate = delegate;
        }

        public interface TaskDelegate {
            public void onTaskEndWithResult(String[] parseLine);
        }

        @Override
        protected String[] doInBackground(String... nextLine) {
            try {
                return parseLine(nextLine[0]);
            } catch (IOException ex) {
                Log.e("CsvReader", ex.getMessage());
            }
            return null;
        }

        @Override
        protected void onPostExecute(String[] parseLine) {
            if (parseLine != null && delegate != null)
                delegate.onTaskEndWithResult(parseLine);
        }
    }

private static final class GetNextLine extends AsyncTask<Void, Integer, String>
        implements ParseLine.TaskDelegate {

        private List<String[]> list;

        public GetNextLine(List<String[]> l) {
            list = l;
        }

        @Override
        protected String doInBackground(Void... companies) {
            try {
                return getNextLine();
            } catch (IOException ex) {
                Log.e("CsvReader", ex.getMessage());
            }
            return null;
        }

        @Override
        protected void onPostExecute(String nextLine) {
            if (nextLine != null) {
                ParseLine parseLine = new ParseLine(this);
                parseLine.execute(nextLine);
            }
        }

        @Override
        public void onTaskEndWithResult(String[] parseLine) {
            list.add(parseLine);
        }
    }