code: def test_bad_formatstr(self):
      p = poly.Polynomial([1, 2, 0, -1])
      with pytest.raises(ValueError):
          format(p, ".2f")
  
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 4 for calling the TestFormat obj's underlying member method code with example usage: obj.test_bad_formatstr() without return types