code: def test_mask_invalid_locations(self):
      hidden_states = self._get_hidden_states()
  
      batch_size = 1
      seq_length = 8
      hidden_size = 4
      hidden_states = hidden_states.reshape(
          (batch_size, seq_length, hidden_size)
      )
      chunked_hidden_states = LongformerSelfAttention._chunk(
          hidden_states, window_overlap=2
      )
  
      hid_states_1 = chunked_hidden_states.clone()
      LongformerSelfAttention._mask_invalid_locations(hid_states_1, 1)
      self.assertTrue(torch.isinf(hid_states_1).sum().item() == 8)
  
      hid_states_2 = chunked_hidden_states.clone()
      LongformerSelfAttention._mask_invalid_locations(hid_states_2, 2)
      self.assertTrue(torch.isinf(hid_states_2).sum().item() == 24)
  
      hid_states_3 = chunked_hidden_states.clone()[:, :, :, :3]
      LongformerSelfAttention._mask_invalid_locations(hid_states_3, 2)
      self.assertTrue(torch.isinf(hid_states_3).sum().item() == 24)
  
      hid_states_4 = chunked_hidden_states.clone()[:, :, 2:, :]
      LongformerSelfAttention._mask_invalid_locations(hid_states_4, 2)
      self.assertTrue(torch.isinf(hid_states_4).sum().item() == 12)
  
imports: import unittest
  from transformers import LongformerConfig, is_torch_available
  from transformers.testing_utils import require_sentencepiece, require_tokenizers, 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 5 for calling the LongformerModelIntegrationTest obj's underlying member method code with example usage: obj.test_mask_invalid_locations() without return types