code: def test_update():
      tracker = SQLiteTracker(":memory:")
      uuid = tracker.new()
      tracker.update(uuid, {})
      res = tracker[uuid]
      assert len(res) == 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 6 for calling a global function with example usage: test_update() without return types