code: def test_different_lengths(self):
      a = [dict(x=1)]
      b = []
  
      with pytest.raises(ValueError):
          c = utils.merge_params(a, b)
  
imports: from unittest import TestCase
  import pytest
  from elegy import utils
label_desc: Use image node_id 5 for calling the TestMergeStructs obj's underlying member method code with example usage: obj.test_different_lengths() without return types