old_contents: random_sample = None
  
new_contents: import random
  from numpy import zeros
  def random_sample(length=0):
      if length == 0:
          return random.random()
      ret = zeros((length,))
      for x in xrange(length):
          ret[x] = random.random()
      return ret
  
  def randn(length=0):
      if length == 0:
          return random.gauss(0., 1.)
      ret = zeros((length,))
      for x in xrange(length):
          ret[x] = random.gauss(0., 1.)
      return ret
  
subject: implement just enough of mtrand to make tests start passing