code: def test_single_line(self):
      class A:
          a = 1
  
      b = 2
      assert A.a == b, "A.a appears not to be b"
  
imports: import pytest
  from pytest import raises
label_desc: Use image node_id 1 for calling the TestCustomAssertMsg obj's underlying member method code with example usage: obj.test_single_line() without return types