old_contents: import sys
  sys.path.append('../mbus')
  import pytest
  
  from mbus import *
  
  def test_empty_init():
      foo = MBus()
  
new_contents: import sys
  sys.path.append('../mbus')
  import pytest
  from mbus import MBus
  
  def test_empty_init():
      foo = MBus.MBus()
  
subject: test for empty constructor added