code: def test_getitem():
      tracker = SQLiteTracker(":memory:")
      tracker.insert("some_uuid", {"a": 1})
      res = tracker["some_uuid"]
      parameters = res.loc["some_uuid"].parameters
  
      assert len(res) == 1
      assert parameters == '{"a": 1}'
  
imports: import json
  from uuid import uuid4
  import time
  import pytest
  from sklearn_evaluation.tracker import SQLiteTracker
  from sklearn_evaluation import tracker
  from sklearn_evaluation import plot
label_desc: Use image node_id 4 for calling a global function with example usage: test_getitem() without return types