code: def to_device(self, dst, size, offset=0, stream=None):
      src = self.memory + offset
      xp = chainer.backend.get_array_module(dst)
      if xp == cp:
          dst_data = dst.data
      elif xp == chx:
          dst_data = _get_memory_pointer_from_chainerx(dst)
      else:
          raise ValueError(
              "{} is from an unsupported array module".format(type(dst))
          )
      if stream is None:
          dst_data.copy_from_device(src, size)
      else:
          dst_data.copy_from_device_async(src, size, stream)
  
imports: import ctypes
  import mpi4py.MPI
  import numpy
  from chainermn.communicators import _communication_utility
  import chainer.backends
  import chainerx
label_desc: Use image node_id 4 for calling the DeviceMemory obj's underlying member method code with example usage: obj.to_device(dst, size, offset, stream) without return types