code: def move_up_policy(board, ship):
      act = nearby_enemy(board, ship)
      if act is not None:
          ship.next_action = act
      else:
          ship.next_action = ShipAction.UP
  
imports: import pickle
  import base64
  import random
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.distributions import Categorical
  from zerosum_env.envs.halite.helpers import *
  from zerosum_env import make, evaluate
  from collections import deque
  import os
label_desc: Use image node_id 18 for calling a global function with example usage: move_up_policy(board, ship) without return types