docs: def run_breiman2():
      """Run Breiman's other sample problem."""
      x, y = build_sample_ace_problem_breiman2(500)
      ace_solver = ace.ACESolver()
      ace_solver.specify_data_set(x, y)
      ace_solver.solve()
      try:
          plt = ace.plot_transforms(ace_solver, None)
      except ImportError:
          pass
  
      plt.subplot(1, 2, 1)
      phi = numpy.sin(2.0 * numpy.pi * x[0])
      plt.plot(x[0], phi, label='analytic')
      plt.legend()
      plt.subplot(1, 2, 2)
      y = numpy.exp(phi)
      plt.plot(y, phi, label='analytic')
      plt.legend(loc='lower right')
      # plt.show()
      plt.savefig('no_noise_linear_x.png')
  
      return ace_solver