code: def _get_possible_devices():
      # Return all the possible usable devices
      with BackendHandler.update_backend(
          test_globals.CURRENT_BACKEND
      ) as ivy_backend:
          devices = ["cpu"]
          if ivy_backend.gpu_is_available():
              for i in range(ivy_backend.num_gpus()):
                  devices.append("gpu:" + str(i))
  
          # Return a list of ivy devices
          return list(map(ivy_backend.Device, devices))
  
imports: import io
  import multiprocessing
  import os
  import re
  import shutil
  import sys
  import warnings
  import numpy
  import psutil
  import subprocess
  from hypothesis import strategies, assume
  import ivy
  import ivy_tests.test_ivy.helpers
  import ivy_tests.test_ivy.helpers.globals
  from ivy_tests.test_ivy.helpers import handle_test, BackendHandler
label_desc: Use image node_id 5 for calling a global function with example usage: _get_possible_devices() and returns: list