new_contents: bsTgt = cmds.ls(sl=1,fl=1)
  newSp = bsTgt[0]
  orgSp = bsTgt[1]
  bsNd = cmds.blendShape(newSp,orgSp)
  cmds.setAttr(bsNd[0]+'.'+newSp,1)
  cmds.select(orgSp,r=1)
  mel.eval('DeleteHistory')
  
subject: Create updateBlendshapes.py