class_docstr: Service that resuscitates itself if it is not available. 
code: def start(self):
      if self.start_cmd:
          if self.host and self.port:
              with contextlib.closing(
                  socket.socket(socket.AF_INET, socket.SOCK_STREAM)
              ) as sock:
                  try:
                      sock.bind((self.host, self.port))
                  except socket.error as e:
                      if self.ignore_binding_error:
                          logger.info(
                              f"Connecting to existing CoreNLP server at {self.host}:{self.port}"
                          )
                          self.server = None
                          return
                      else:
                          raise PermanentlyFailedException(
                              "Error: unable to start the CoreNLP server on port %d "
                              "(possibly something is already running there)"
                              % self.port
                          ) from e
          if self.be_quiet:
              # Issue #26: subprocess.DEVNULL isn't supported in python 2.7.
              if hasattr(subprocess, "DEVNULL"):
                  stderr = subprocess.DEVNULL
              else:
                  stderr = open(os.devnull, "w")
              stdout = stderr
          else:
              stdout = self.stdout
              stderr = self.stderr
          logger.info(
              f"Starting server with command: {' '.join(self.start_cmd)}"
          )
          try:
              self.server = subprocess.Popen(
                  self.start_cmd, stderr=stderr, stdout=stdout
              )
          except FileNotFoundError as e:
              raise FileNotFoundError(
                  "When trying to run CoreNLP, a FileNotFoundError occurred, which frequently means Java was not installed or was not in the classpath."
              ) from e
  
imports: import atexit
  import contextlib
  import enum
  import io
  import os
  import re
  import requests
  import logging
  import json
  import shlex
  import socket
  import subprocess
  import time
  import sys
  import uuid
  from datetime import datetime
  from pathlib import Path
  from urllib.parse import urlparse
  from stanza.protobuf import Document, parseFromDelimitedString, writeToDelimitedString, to_text
label_desc: Use image node_id 3 for calling the RobustService obj's underlying member method code with example usage: obj.start() without return types