code: def test_hierarchy(self):
      a = dict(a=dict(x=1))
      b = dict(a=dict(y=2))
  
      c = utils.merge_params(a, b)
  
      assert c == {"a": {"x": 1, "y": 2}}
  
imports: from unittest import TestCase
  import pytest
  from elegy import utils
label_desc: Use image node_id 2 for calling the TestMergeStructs obj's underlying member method code with example usage: obj.test_hierarchy() without return types