code: def test_parameters_valuesdict(parameters):
      """Test for valuesdict method."""
      pars, _, _ = parameters
      vals_dict = pars.valuesdict()
  
      assert isinstance(vals_dict, dict)
      assert_allclose(vals_dict["a"], pars["a"].value)
      assert_allclose(vals_dict["b"], pars["b"].value)
  
imports: from copy import copy, deepcopy
  import os
  import pickle
  import numpy
  from numpy.testing import assert_allclose
  import pytest
  import lmfit
  from lmfit.models import VoigtModel
label_desc: Use image node_id 24 for calling a global function with example usage: test_parameters_valuesdict(parameters) without return types