new_contents: import pytest
  import odl
  import odl.contrib.fom
  import odl.contrib.param_opt
  from odl.util.testutils import simple_fixture
  
  space = simple_fixture('space',
                         [odl.rn(3),
                          odl.uniform_discr([0, 0], [1, 1], [9, 11]),
                          odl.uniform_discr(0, 1, 10)])
  
  def test_optimal_parameters(space):
      """Tests if optimal_parameters works for some simple examples."""
      fom = odl.contrib.fom.mean_squared_error
      mynoise = odl.phantom.white_noise(space)
      phantoms = [mynoise]
      data = [mynoise]
  
      def reconstruction(data, lam):
          """Perturbs the data by adding lam to it."""
          return data + lam
  
      result = odl.contrib.param_opt.optimal_parameters(reconstruction, fom,
                                                        phantoms, data, 1)
      assert result == pytest.approx(0)
  
  
  if __name__ == '__main__':
      odl.util.test_file(__file__)
  
subject: Add initial test for the optimal_parameters function.