code: def testMultiMeshHostDeviceTransfer(
      self, host_to_dev, sharded, dtype
  ):
      self.skipForDeviceType(
          ["CPU"],
          "Skipping test as only CPU mesh is available for multi-meshtest.",
      )
  
      def run_copy_to_mesh(data, src_layout, dst_layout):
          @polymorphic_function.function
          def func(x):
              return api.copy_to_mesh(x, dst_layout)
  
          if src_layout.is_fully_replicated():
              src_data = api.copy_to_mesh(data, src_layout)
          else:
              src_data = api.copy_to_mesh(
                  data,
                  Layout.replicated(
                      src_layout.mesh, rank=len(data.shape)
                  ),
              )
              src_data = api.relayout(src_data, src_layout)
          dst_data = func(src_data)
          return (src_data, dst_data)
  
      dev_mesh = self.first_mesh
      cpu_mesh = self.second_mesh
  
      if host_to_dev:
          src_mesh, dst_mesh = cpu_mesh, dev_mesh
      else:
          src_mesh, dst_mesh = dev_mesh, cpu_mesh
  
      if sharded:
          src_layout = Layout.batch_sharded(
              src_mesh, src_mesh.dim_names[0], rank=2
          )
          dst_layout = Layout.batch_sharded(
              dst_mesh, dst_mesh.dim_names[0], rank=2
          )
      else:
          src_layout = Layout.replicated(src_mesh, rank=2)
          dst_layout = Layout.replicated(dst_mesh, rank=2)
  
      data = array_ops.ones([8, 8], dtype=dtype)
      src, dst = run_copy_to_mesh(data, src_layout, dst_layout)
      self.assertDTensorEqual(data, src_layout, src)
      self.assertDTensorEqual(data, dst_layout, dst)
  
imports: from absl.testing import parameterized
  import numpy
  from tensorflow.dtensor.python import accelerator_util
  from tensorflow.dtensor.python import api
  from tensorflow.dtensor.python import config
  from tensorflow.dtensor.python import d_variable
  from tensorflow.dtensor.python import layout
  from tensorflow.dtensor.python.tests import test_util
  from tensorflow.python.eager import backprop
  from tensorflow.python.eager import context
  from tensorflow.python.eager.polymorphic_function import polymorphic_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors_impl
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gen_math_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 18 for calling the MultiMeshTest obj's underlying member method code with example usage: obj.testMultiMeshHostDeviceTransfer(host_to_dev, sharded, dtype) and returns: src_data,  dst_data, api