code: @Override
    public void enqueueCall(final Callback<DirectionsResponse> callback) {
      getCall().enqueue(new Callback<DirectionsResponse>() {
        @Override
        public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
          DirectionsResponseFactory factory = new DirectionsResponseFactory(MapboxDirections.this);
          Response<DirectionsResponse> generatedResponse = factory.generate(response);
          callback.onResponse(call, generatedResponse);
        }
  
        @Override
        public void onFailure(Call<DirectionsResponse> call, Throwable throwable) {
          callback.onFailure(call, throwable);
        }
      });
    }
docs: Wrapper method for Retrofits {@link Call#enqueue(Callback)} call returning a response specific
  to the Directions API. Use this method to make a directions request on the Main Thread.
  
  @param callback a {@link Callback} which is used once the {@link DirectionsResponse} is
  created.
  @since 1.0.0