code: def test_confidence_2d(data, pars):
      """Test the 2D confidence interval calculation."""
      minimizer = lmfit.Minimizer(residual, pars, fcn_args=data)
      out = minimizer.minimize(method="leastsq")
  
      cx, cy, grid = lmfit.conf_interval2d(
          minimizer, out, "a", "b", 30, 20
      )
      assert len(cx.ravel()) == 30
      assert len(cy.ravel()) == 20
      assert grid.shape == (20, 30)
  
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 13 for calling a global function with example usage: test_confidence_2d(data, pars) without return types