class_docstr: Exception thrown for an unsuccessful HTTP request.
  
  Attributes:
  
  * ``code`` - HTTP error integer error code, e.g. 404.  Error code 599 is
    used when no HTTP response was received, e.g. for a timeout.
  
  * ``response`` - `HTTPResponse` object, if any.
  
  Note that if ``follow_redirects`` is False, redirects become HTTPErrors,
  and you can look at ``error.response.headers['Location']`` to see the
  destination of the redirect.
  
  .. versionchanged:: 5.1
  
     Renamed from ``HTTPError`` to ``HTTPClientError`` to avoid collisions with
     `tornado.web.HTTPError`. The name ``tornado.httpclient.HTTPError`` remains
     as an alias.
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code: def __init__(
      self,
      code: int,
      message: Optional[str] = None,
      response: Optional[HTTPResponse] = None,
  ) -> None:
      self.code = code
      self.message = message or httputil.responses.get(code, "Unknown")
      self.response = response
      super().__init__(code, message, response)
  
imports: import datetime
  import functools
  from io import BytesIO
  import ssl
  import time
  import weakref
  from tornado.concurrent import Future, future_set_result_unless_cancelled, future_set_exception_unless_cancelled
  from tornado.escape import utf8, native_str
  from tornado import gen, httputil
  from tornado.ioloop import IOLoop
  from tornado.util import Configurable
  from typing import Type, Any, Union, Dict, Callable, Optional, cast
label_desc: Use image node_id 1 to create a new HTTPClientError object from inherited base classes: Exception with example: obj = HTTPClientError(code, message, response)