class_docstr: Shipper reads structured logs from logq and ships them to the determined-master.
  
  It will send a message on doneq when it finishes.
code: def try_reaching_master(self) -> bool:
      endpoint = "/api/v1/me"
      url = f"{self.base_url}{endpoint}"
      req = urllib.request.Request(url, headers=self.headers)
      try:
          with urllib.request.urlopen(
              req, context=self.context
          ) as resp:
              _ = resp.read()
          return True
      except Exception as e:
          # urllib stacktraces are awful, so in cases where we can tell what happened, avoid
          # printing it at all.
          exc_info = True
          detail = (
              "This may be due to an address resolution problem, a certificate problem, a "
              "firewall problem, a proxy problem, or some other networking error."
          )
          if isinstance(e, urllib.error.HTTPError):
              detail = f"GET {url} returned status code: {e.code} and reason: {e.reason}."
              exc_info = False
          elif isinstance(e, urllib.error.URLError):
              if isinstance(e.reason, socket.gaierror):
                  detail = f"Name lookup for {self.master_url} failed: {e.reason}"
                  exc_info = False
              elif isinstance(e.reason, ConnectionRefusedError):
                  detail = f"The connection to {self.master_url} was refused."
                  exc_info = False
              elif isinstance(e.reason, ssl.SSLCertVerificationError):
                  detail = f"There was a tls verification error: {e.reason.verify_message}."
                  exc_info = False
  
          if self.master_url.lower().startswith("https"):
              proxy_name_lower = "https_proxy"
              proxy_name_upper = "HTTPS_PROXY"
          else:
              proxy_name_lower = "http_proxy"
              proxy_name_upper = "HTTP_PROXY"
  
          proxy_value_lower = os.environ.get(proxy_name_lower)
          proxy_value_upper = os.environ.get(proxy_name_upper)
  
          no_proxy_value_lower = os.environ.get("no_proxy")
          no_proxy_value_upper = os.environ.get("NO_PROXY")
  
          logging.error(
              f"Unable to reach the master at DET_MASTER={self.master_url}.  {detail}\n"
              "Debug information:\n"
              f"    master_url: {self.master_url}\n"
              f"    endpoint: {url}\n"
              f"    tls_verify_name: {self.cert_name or None}\n"
              f"    tls_noverify: {self.noverify}\n"
              f"    tls_cert: {self.cert_content}\n"
              f"    {proxy_name_lower}: {proxy_value_lower}\n"
              f"    {proxy_name_upper}: {proxy_value_upper}\n"
              f"    no_proxy: {no_proxy_value_lower}\n"
              f"    NO_PROXY: {no_proxy_value_upper}\n",
              exc_info=exc_info,
          )
          return False
  
imports: import datetime
  import io
  import json
  import logging
  import os
  import queue
  import re
  import signal
  import socket
  import ssl
  import subprocess
  import sys
  import threading
  import time
  import traceback
  import urllib.error
  import urllib.request
  from typing import Any, Dict, Iterator, List, NamedTuple, Optional, cast
label_desc: Use image node_id 7 for calling the Shipper obj's underlying member method code with example usage: obj.try_reaching_master() and returns: True, False