code: def test_upsert():
      tracker = SQLiteTracker(":memory:")
  
      uuid = tracker.new()
      tracker.update(uuid, dict(a=1, b=2))
      tracker.upsert(uuid, dict(a=2, c=3))
  
      assert tracker.get(uuid) == dict(a=2, b=2, c=3)
      assert len(tracker) == 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 10 for calling a global function with example usage: test_upsert() without return types