code: def check_existence(filename):
      """Check the existence of file or dir."""
      if not os.path.exists(filename):
          raise RuntimeError(
              "%s not found. Are you under the TensorFlow source root"
              " directory?" % filename
          )
  
imports: import argparse
  import os
  import re
  import subprocess
  import time
label_desc: Use image node_id 1 for calling a global function with example usage: check_existence(filename) without return types