code: def test_ufloat():
      """Test of ufloat from uncertainties."""
      x = ufloat(1, 0.1)
      assert_allclose(x.nominal_value, 1.0, rtol=1.0e-7)
      assert_allclose(x.std_dev, 0.1, rtol=1.0e-7)
  
      y = x * x
      assert_allclose(y.nominal_value, 1.0, rtol=1.0e-7)
      assert_allclose(y.std_dev, 0.2, rtol=1.0e-7)
  
      y = x - x
      assert_allclose(y.nominal_value, 0.0, rtol=1.0e-7)
      assert_allclose(y.std_dev, 0.0, rtol=1.0e-7)
  
imports: import sys
  import unittest
  import numpy
  from numpy import pi
  from numpy.testing import assert_allclose, assert_almost_equal, assert_equal
  import pytest
  from scipy.optimize import rosen_der
  from uncertainties import ufloat
  from lmfit import Minimizer, Parameters, minimize
  from lmfit.lineshapes import gaussian
  from lmfit.minimizer import HAS_EMCEE, SCALAR_METHODS, MinimizerResult, coerce_float64
  from lmfit.models import SineModel
label_desc: Use image node_id 11 for calling a global function with example usage: test_ufloat() without return types