code: def _test_init(self, cls, **params):
      encoder = cls.from_params(**params)
      self.assertTrue(isinstance(encoder, nn.Module))
  
imports: import tempfile
  import unittest
  import torch
  from mmf.modules import encoders
  from omegaconf import OmegaConf
  from tests.test_utils import setup_proxy, skip_if_no_pytorchvideo, skip_if_old_transformers
  from torch import nn
label_desc: Use image node_id 2 for calling the TestEncoders obj's underlying member method code with example usage: obj._test_init(cls) without return types