code: def is_return_code_zero(args):
      """Return `True` if the return code of the given command
      is zero.
  
      All the messages sent to stdout or stderr are suppressed.
  
      Args:
          args (list of str): A command to execute.
  
      """
  
      with open(os.devnull, "wb") as FNULL:
          try:
              subprocess.check_call(args, stdout=FNULL, stderr=FNULL)
          except subprocess.CalledProcessError:
              # The given command returned an error
              return False
          except OSError:
              # The given command was not found
              return False
          return True
  
file_path: chainer/chainer/training/extensions/computational_graph.py
imports: import os
  import subprocess
  from chainer import computational_graph
  from chainer import configuration
  from chainer.training import extension
  from chainer.utils import argument
  from chainer import variable
label_desc: Use image node_id 1 for calling a global function with example usage: is_return_code_zero(args) and returns: True, False, False