code: def test_init_changed_config(self):
      config = self.model_tester.prepare_config_and_inputs()[0]
  
      model = DPRQuestionEncoder(config=config)
      model.to(torch_device)
      model.eval()
  
      with tempfile.TemporaryDirectory() as tmp_dirname:
          model.save_pretrained(tmp_dirname)
          model = DPRQuestionEncoder.from_pretrained(
              tmp_dirname, projection_dim=512
          )
  
      self.assertIsNotNone(model)
  
imports: import tempfile
  import unittest
  from transformers import DPRConfig, is_torch_available
  from transformers.testing_utils import require_torch, slow, torch_device
  from ...test_configuration_common import ConfigTester
  from ...test_modeling_common import ModelTesterMixin, ids_tensor, random_attention_mask
label_desc: Use image node_id 6 for calling the DPRModelTest obj's underlying member method code with example usage: obj.test_init_changed_config() without return types