code: def set_gpu(flag=True):
      __builtins__["__DYNET_GPU"] = flag
      if "__DYNET_CONFIG" in __builtins__:
          __builtins__["__DYNET_CONFIG"]["requested_gpus"] = 1
      else:
          set(requested_gpus=1)
  
label_desc: Use image node_id 2 for calling a global function with example usage: set_gpu(flag) without return types