old_contents: "doc"
  
  def xx(**kw):
      pass
  
  def yy():
      c = yy
      g, h = 1, 2
      xx(a='', b=c.a.d.f, e=5, jj=xx(j=5), f=(g+h))
  
  def zz():
      b = zz
      xx(b=(1, 2, 3), c={ 'a': b}, d=[1, 2, 3], k=(1 < 2))
  
  
new_contents: "doc"
  
  def xx(**kw):
      pass
  
  def yy():
      c = yy
      g, h = 1, 2
      xx(a='', b=c.a.d.f, e=5, jj=xx(j=5), f=(g+h), k=("%s" % "df"))
  
  def zz():
      b = zz
      xx(b=(1, 2, 3), c={ 'a': b}, d=[1, 2, 3], k=(1 < 2))
  
  
subject: make test a little harder