code: def execute_combine(cls, ctx, op):
      axis = cls.get_axis(op.axis)
      (_data, _count), device_id, xp = as_same_device(
          ctx[op.inputs[0].key], device=op.device, ret_extra=True
      )
  
      with device(device_id):
          chunk_count = xp.sum(
              _count,
              axis=axis,
              dtype=np.int64,
              keepdims=bool(op.keepdims),
          )
          chunk_sum = xp.sum(
              _data,
              axis=axis,
              dtype=op.dtype,
              keepdims=bool(op.keepdims),
          )
          ctx[op.outputs[0].key] = (chunk_sum, chunk_count)
  
file_path: mars/mars/tensor/reduction/mean.py
imports: import numpy
  from ...None import opcodes
  from ..datasource import tensor
  from ..array_utils import as_same_device, device
  from .core import TensorReduction, TensorReductionMixin, numel
label_desc: Use image node_id 4 for calling the TensorMean obj's underlying member method code with example usage: obj.execute_combine(cls, ctx, op) without return types