code: def test_get_parameters_keys():
      tracker = SQLiteTracker(":memory:")
  
      to_insert = [
          dict(a=1, b=2),
          dict(x=1, y=2),
          dict(z=3),
      ]
  
      for i, data in enumerate(to_insert):
          tracker.insert(i, data)
  
      assert tracker.get_parameters_keys() == ["a", "b", "x", "y", "z"]
  
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 14 for calling a global function with example usage: test_get_parameters_keys() without return types