code: def mirrorY(self):
      if not self.isMovable():
          return
  
      # flip = self.transformGui.mirrorImageCheck.isChecked()
      # tr = self.userTransform.saveState()
  
      inv = SRTTransform()
      inv.scale(-1, 1)
      self.userTransform = self.userTransform * inv
      self.updateTransform()
      self.selectBoxFromUser()
      self.sigTransformChangeFinished.emit(self)
  
imports: import importlib
  from ..None import ItemGroup, SRTTransform, debug
  from ..None import functions
  from ..graphicsItems.ROI import ROI
  from ..Qt import QT_LIB, QtCore, QtWidgets
  from .None import TransformGuiTemplate_generic
label_desc: Use image node_id 9 for calling the CanvasItem obj's underlying member method code with example usage: obj.mirrorY() without return types