code: def test_format_ascii(self):
      poly.set_default_printstyle("unicode")
      p = poly.Polynomial([1, 2, 0, -1])
      assert_equal(
          format(p, "ascii"), "1.0 + 2.0 x + 0.0 x**2 - 1.0 x**3"
      )
  
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 2 for calling the TestFormat obj's underlying member method code with example usage: obj.test_format_ascii() without return types