old_contents: has_qt = True
  
  try:
      from matplotlib.backends.qt_compat import QtGui, QtCore, QtWidgets
  except ImportError:
      try:
          from matplotlib.backends.qt4_compat import QtGui, QtCore
          QtWidgets = QtGui
      except ImportError:
          # Mock objects
          class QtGui(object):
              QMainWindow = object
              QDialog = object
              QWidget = object
  
          class QtCore_cls(object):
              Qt = object
  
              def Signal(self, *args, **kwargs): 
                  pass
  
          QtCore = QtCore_cls()
          QtWidgets = QtGui
  
          has_qt = False
  
  Qt = QtCore.Qt
  Signal = QtCore.Signal
  
new_contents: has_qt = True
  
  try:
      from matplotlib.backends.qt_compat import QtGui, QtCore, QtWidgets
  except ImportError:
      try:
          from matplotlib.backends.qt4_compat import QtGui, QtCore
          QtWidgets = QtGui
      except ImportError:
          # Mock objects
          class QtGui(object):
              QMainWindow = object
              QDialog = object
              QWidget = object
  
          class QtCore_cls(object):
              class Qt(object):
                   TopDockWidgetArea = None
                   BottomDockWidgetArea = None
                   LeftDockWidgetArea = None
                   RightDockWidgetArea = None
  
              def Signal(self, *args, **kwargs): 
                  pass
  
          QtCore = QtWidgets = QtCore_cls()
  
          has_qt = False
  
  Qt = QtCore.Qt
  Signal = QtCore.Signal
  
subject: Add dummy Qt properties