old_contents: import numpy as np
  
  import chainer
  from chainer import functions as F
  from chainer import links as L
  
  import v_function
  import dqn_net
  
  
  class FCTailVFunction(chainer.ChainList, v_function.VFunction):
  
      def __init__(self, head, head_output_size):
  
          layers = [
              head.copy(),
              L.Linear(head_output_size, 1),
          ]
  
          super(FCTailVFunction, self).__init__(*layers)
  
      def __call__(self, state):
          h = self[0](state)
          return self[1](h)
  
new_contents: import chainer
  from chainer import links as L
  
  import v_function
  
  
  class FCTailVFunction(chainer.ChainList, v_function.VFunction):
  
      def __init__(self, head, head_output_size):
  
          layers = [
              head.copy(),
              L.Linear(head_output_size, 1),
          ]
  
          super(FCTailVFunction, self).__init__(*layers)
  
      def __call__(self, state):
          h = self[0](state)
          return self[1](h)
  
subject: Remove unused imports