code: def validate_multiprocessing_workers(
      tape: qml.tape.QuantumTape, max_workers: int, device
  ) -> (Sequence[qml.tape.QuantumTape], Callable):
      """Validates the number of workers for multiprocessing.
  
      Checks that the CPU is not oversubscribed and warns user if it is,
      making suggestions for the number of workers and/or the number of
      threads per worker.
  
      Args:
          tape (QuantumTape or .QNode or Callable): a quantum circuit.
          max_workers (int): Maximal number of multiprocessing workers
          device (pennylane.devices.Device): The device to be checked.
  
      Returns:
          qnode (pennylane.QNode) or quantum function (callable) or tuple[List[.QuantumTape], function]:
  
          The unaltered input circuit. The output type is explained in :func:`qml.transform <pennylane.transform>`.
  
      """
      if max_workers is not None:
          threads_per_proc = os.cpu_count()  # all threads by default
          varname = "OMP_NUM_THREADS"
          varnames = [
              "MKL_NUM_THREADS",
              "OPENBLAS_NUM_THREADS",
              "OMP_NUM_THREADS",
          ]
          for var in varnames:
              if os.getenv(var):  # pragma: no cover
                  varname = var
                  threads_per_proc = int(os.getenv(var))
                  break
          num_threads = threads_per_proc * max_workers
          num_cpu = os.cpu_count()
          num_threads_suggest = max(1, os.cpu_count() // max_workers)
          num_workers_suggest = max(
              1, os.cpu_count() // threads_per_proc
          )
          if num_threads > num_cpu:
              warnings.warn(
                  f"""The device requested {num_threads} threads ({max_workers} processes
                  times {threads_per_proc} threads per process), but the processor only has
                  {num_cpu} logical cores. The processor is likely oversubscribed, which may
                  lead to performance deterioration. Consider decreasing the number of processes,
                  setting the device or execution config argument `max_workers={num_workers_suggest}`
                  for example, or decreasing the number of threads per process by setting the
                  environment variable `{varname}={num_threads_suggest}`.""",
                  UserWarning,
              )
  
          if device._debugger and device._debugger.active:
              raise DeviceError(
                  "Debugging with ``Snapshots`` is not available with multiprocessing."
              )
  
          if any(isinstance(op, Snapshot) for op in tape.operations):
              raise RuntimeError(
                  """ProcessPoolExecutor cannot execute a QuantumScript with
                  a ``Snapshot`` operation. Change the value of ``max_workers``
                  to ``None`` or execute the QuantumScript separately."""
              )
  
      return (tape,), null_postprocessing
  
imports: import os
  from typing import Generator, Callable, Union, Sequence, Optional
  from copy import copy
  import warnings
  import pennylane
  from pennylane import Snapshot
  from pennylane.operation import Tensor, StatePrepBase
  from pennylane.measurements import MeasurementProcess, StateMeasurement, SampleMeasurement
  from pennylane.typing import ResultBatch, Result
  from pennylane import DeviceError
  from pennylane import transform
  from pennylane.wires import WireError
label_desc: Use image node_id 5 for calling a global function with example usage: validate_multiprocessing_workers(tape, max_workers, device) and returns: tape,  null_postprocessing