code: def get_gpu_mem_usage(backend, device="gpu:0"):
      handle = backend.ivy.functional.ivy.device._get_nvml_gpu_handle(
          device
      )
      info = pynvml.nvmlDeviceGetMemoryInfo(handle)
      return (info.used / info.total) * 100
  
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 8 for calling a global function with example usage: get_gpu_mem_usage(backend, device) and returns: unknown