code: def test_strategy_assertion(self):
      self.assertRaises(
          ValueError, lambda: BatchEasyHardMiner(pos_strategy="blah")
      )
      self.assertRaises(
          ValueError,
          lambda: BatchEasyHardMiner(
              pos_strategy="semihard", neg_strategy="semihard"
          ),
      )
      self.assertRaises(
          ValueError,
          lambda: BatchEasyHardMiner(
              pos_strategy="all", neg_strategy="semihard"
          ),
      )
      self.assertRaises(
          ValueError,
          lambda: BatchEasyHardMiner(
              pos_strategy="semihard", neg_strategy="all"
          ),
      )
  
file_path: pytorch-metric-learning/tests/miners/test_batch_easy_hard_miner.py
imports: import unittest
  import torch
  from pytorch_metric_learning.distances import LpDistance
  from pytorch_metric_learning.miners import BatchEasyHardMiner
  from pytorch_metric_learning.utils import loss_and_miner_utils
  from ..None import TEST_DEVICE, TEST_DTYPES, WITH_COLLECT_STATS
label_desc: Use image node_id 3 for calling the TestBatchEasyHardMiner obj's underlying member method code with example usage: obj.test_strategy_assertion() without return types