code: def _most_nbytes_device(device_nbytes):
      device_to_nbytes = defaultdict(lambda: 0)
      for device, nbytes in device_nbytes:
          device_to_nbytes[device] += nbytes
      return max(device_to_nbytes, key=lambda i: device_to_nbytes[i])
  
file_path: mars/mars/tensor/array_utils.py
imports: from collections import defaultdict
  from contextlib import contextmanager
  import numpy
  from ..lib import sparse
  from ..lib.sparse.core import issparse, get_dense_module
  from ..utils import lazy_import
label_desc: Use image node_id 8 for calling a global function with example usage: _most_nbytes_device(device_nbytes) and returns: max