code: def _MaybeDevice(device):
      """Applies the given device only if device is not None or empty."""
      if device:
          with ops.device(device):
              yield
      else:
          yield
  
imports: import contextlib
  from tensorflow.core.framework import graph_pb2
  from tensorflow.python import tf2
  from tensorflow.python.client import pywrap_tf_session
  from tensorflow.python.framework import c_api_util
  from tensorflow.python.framework import device
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import function
  from tensorflow.python.framework import op_def_registry
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import control_flow_util
  from tensorflow.python.util import compat
  from tensorflow.python.util.deprecation import deprecated_args
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 3 for calling a global function with example usage: _MaybeDevice(device) without return types