new_contents: print "import..."
  from timeit import default_timer as clock
  from sage.all import var
  var("x")
  e = 1
  print "constructing expression..."
  for i in range(1, 351):
      e *= (i+x)**3
  print "running benchmark..."
  t1 = clock()
  f = e.expand()
  t2 = clock()
  print "Total time:", t2-t1, "s"
  
subject: Add Sage benchmark for expand4