code: def test_implicit(self):
      implicit_mod = Model(
          self.implicit_fcn,
          implicit=1,
          meta=dict(
              name="Sample Implicit Model", ref="ODRPACK UG, pg. 49"
          ),
      )
      implicit_dat = Data(
          [
              [
                  0.5,
                  1.2,
                  1.6,
                  1.86,
                  2.12,
                  2.36,
                  2.44,
                  2.36,
                  2.06,
                  1.74,
                  1.34,
                  0.9,
                  -0.28,
                  -0.78,
                  -1.36,
                  -1.9,
                  -2.5,
                  -2.88,
                  -3.18,
                  -3.44,
              ],
              [
                  -0.12,
                  -0.6,
                  -1.0,
                  -1.4,
                  -2.54,
                  -3.36,
                  -4.0,
                  -4.75,
                  -5.25,
                  -5.64,
                  -5.97,
                  -6.32,
                  -6.44,
                  -6.44,
                  -6.41,
                  -6.25,
                  -5.88,
                  -5.5,
                  -5.24,
                  -4.86,
              ],
          ],
          1,
      )
      implicit_odr = ODR(
          implicit_dat,
          implicit_mod,
          beta0=[-1.0, -3.0, 0.09, 0.02, 0.08],
      )
  
      out = implicit_odr.run()
      assert_array_almost_equal(
          out.beta,
          np.array(
              [
                  -0.9993809167281279,
                  -2.9310484652026476,
                  0.0875730502693354,
                  0.0162299708984738,
                  0.0797537982976416,
              ]
          ),
      )
      assert_array_almost_equal(
          out.sd_beta,
          np.array(
              [
                  0.1113840353364371,
                  0.1097673310686467,
                  0.0041060738314314,
                  0.0027500347539902,
                  0.0034962501532468,
              ]
          ),
      )
      assert_allclose(
          out.cov_beta,
          np.array(
              [
                  [
                      2.1089274602333052e00,
                      -1.9437686411979040e00,
                      7.0263550868344446e-02,
                      -4.7175267373474862e-02,
                      5.2515575927380355e-02,
                  ],
                  [
                      -1.9437686411979040e00,
                      2.0481509222414456e00,
                      -6.1600515853057307e-02,
                      4.6268827806232933e-02,
                      -5.8822307501391467e-02,
                  ],
                  [
                      7.0263550868344446e-02,
                      -6.1600515853057307e-02,
                      2.8659542561579308e-03,
                      -1.4628662260014491e-03,
                      1.4528860663055824e-03,
                  ],
                  [
                      -4.7175267373474862e-02,
                      4.6268827806232933e-02,
                      -1.4628662260014491e-03,
                      1.2855592885514335e-03,
                      -1.2692942951415293e-03,
                  ],
                  [
                      5.2515575927380355e-02,
                      -5.8822307501391467e-02,
                      1.4528860663055824e-03,
                      -1.2692942951415293e-03,
                      2.0778813389755596e-03,
                  ],
              ]
          ),
          rtol=1e-6,
          atol=2e-6,
      )
  
imports: import tempfile
  import shutil
  import os
  import numpy
  from numpy import pi
  from numpy.testing import assert_array_almost_equal, assert_equal, assert_warns, assert_allclose
  import pytest
  from pytest import raises
  from scipy.odr import Data, Model, ODR, RealData, OdrStop, OdrWarning, multilinear, exponential, unilinear, quadratic, polynomial
label_desc: Use image node_id 9 for calling the TestODR obj's underlying member method code with example usage: obj.test_implicit() without return types