code: def pars():
      """Create and initialize parameter set."""
      parameters = lmfit.Parameters()
      parameters.add_many(("a", 0.1), ("b", 1))
      return parameters
  
imports: import copy
  import numpy
  from numpy.testing import assert_allclose
  import pytest
  from scipy.stats import f
  import lmfit
label_desc: Use image node_id 2 for calling a global function with example usage: pars() and returns: parameters