code: def test_vqa(self):
      model, vis_processors, txt_processors = load_model_and_preprocess(
          name="blip_vqa",
          model_type="vqav2",
          is_eval=True,
          device=device,
      )
  
      # ask a random question.
      question = "Which city is this photo taken?"
  
      image = vis_processors["eval"](raw_image).unsqueeze(0).to(device)
      question = txt_processors["eval"](question)
  
      samples = {"image": image, "text_input": question}
  
      answer = model.predict_answers(
          samples=samples,
          inference_method="generate",
      )
      assert answer == ["singapore"]
  
      answer_list = ["Singapore", "London", "Palo Alto", "Tokyo"]
      answers = model.predict_answers(samples, answer_list=answer_list)
  
      assert answers == ["Singapore"]
  
file_path: lavis/tests/models/test_blip.py
imports: import pytest
  import torch
  from lavis.models import load_model, load_model_and_preprocess
  from PIL import Image
label_desc: Use image node_id 4 for calling the TestBlip obj's underlying member method code with example usage: obj.test_vqa() without return types