code: def test_memory(self, input_param, expected_key_size):
      input_data = {"image": {}} if "sep" in input_param else {}
      for i in range(50):
          if "sep" in input_param:
              input_data["image"][str(i)] = [time.time()] * 100000
          else:
              input_data[str(i)] = [time.time()] * 100000
      result = DeleteItemsd(**input_param)(input_data)
      if "sep" in input_param:
          self.assertEqual(
              len(result["image"].keys()), expected_key_size
          )
      else:
          self.assertEqual(len(result.keys()), expected_key_size)
      self.assertGreaterEqual(
          sys.getsizeof(input_data)
          * float(expected_key_size)
          / len(input_data),
          sys.getsizeof(result),
      )
  
file_path: MONAI/tests/test_delete_itemsd.py
imports: from __future__ import annotations
  import sys
  import time
  import unittest
  from parameterized import parameterized
  from monai.transforms import DeleteItemsd
  from monai.utils.enums import PostFix
label_desc: Use image node_id 1 for calling the TestDeleteItemsd obj's underlying member method code with example usage: obj.test_memory(input_param, expected_key_size) without return types