code: def to_gpu(x, *args, **kwargs):
      '''puts pytorch variable to gpu, if cuda is available and USE_GPU is set to true. '''
      return x.cuda(*args, **kwargs) if USE_GPU else f to_gpu(x, *args, **kwargs):
      '''puts pytorch variable to gpu, if cuda is available and USE_GPU is set to true. '''
      return x.cuda(*args, **kwargs) if USE_GPU else x
docs: puts pytorch variable to gpu, if cuda is available and USE_GPU is set to true.