code: def test_format_unicode(self):
      poly.set_default_printstyle("ascii")
      p = poly.Polynomial([1, 2, 0, -1])
      assert_equal(
          format(p, "unicode"), "1.0 + 2.0·x + 0.0·x² - 1.0·x³"
      )
  
imports: from math import nan, inf
  import pytest
  from numpy._core import array, arange, printoptions
  import numpy.polynomial
  from numpy.testing import assert_equal, assert_
  from fractions import Fraction
  from decimal import Decimal
label_desc: Use image node_id 1 for calling the TestFormat obj's underlying member method code with example usage: obj.test_format_unicode() without return types