@Override
    public void writeToParcel(Parcel out, int flags) {
        // Prepare an array of strings and an array of timestamps.
        String[] texts = new String[mData.size()];
        long[] timestamps = new long[mData.size()];

        // Store the data in the arrays.
        for (int i = 0; i < mData.size(); i++) {
            texts[i] = mData.get(i).first;
            timestamps[i] = mData.get(i).second;
        }
        // Write the size of the arrays first.
        out.writeInt(texts.length);

        // Write the two arrays in a specific order.
        out.writeStringArray(texts);
        out.writeLongArray(timestamps);
    }
Model that stores a parcelable log of entries, each with a timestamp.
unit/BasicUnitAndroidTest/app/src/main/java/com/example/android/testing/unittesting/basicunitandroidtest/LogHistory.java