code: def test_extra_fields_per_instance(self):
      # This test exists to ensure that instances of the same class
      # store their own values for the extra fields. That is, the values
      # are stored per instance and not in the class.
      result1 = Result(x=1, y=2, z=3, w=-1, beta=0.0)
      result2 = Result(x=4, y=5, z=6, w=99, beta=1.0)
      assert_equal(result1.w, -1)
      assert_equal(result1.beta, 0.0)
      # The rest of these checks aren't essential, but let's check
      # them anyway.
      assert_equal(result1[:], (1, 2, 3))
      assert_equal(result2.w, 99)
      assert_equal(result2.beta, 1.0)
      assert_equal(result2[:], (4, 5, 6))
  
imports: import pytest
  import pickle
  from numpy.testing import assert_equal
  from scipy._lib._bunch import _make_tuple_bunch
label_desc: Use image node_id 15 for calling the TestMakeTupleBunch obj's underlying member method code with example usage: obj.test_extra_fields_per_instance() without return types