def urlopen(
        self,
        method,
        url,
        body=None,
        headers=None,
        retries=None,
        redirect=True,
        assert_same_host=True,
        timeout=_Default,
        pool_timeout=None,
        release_conn=None,
        chunked=False,
        body_pos=None,
        **response_kw
    ):
        """
        Get a connection from the pool and perform an HTTP request. This is the
        lowest level call for making a request, so you'll need to specify all
        the raw details.

        .. note::

           More commonly, it's appropriate to use a convenience method provided
           by :class:`.RequestMethods`, such as :meth:`request`.

        .. note::

           `release_conn` will only behave as expected if
           `preload_content=False` because we want to make
           `preload_content=False` the default behaviour someday soon without
           breaking backwards compatibility.

        :param method:
            HTTP request method (such as GET, POST, PUT, etc.)

        :param url:
            The URL to perform the request on.

        :param body:
            Data to send in the request body, either :class:`str`, :class:`bytes`,
            an iterable of :class:`str`/:class:`bytes`, or a file-like object.

        :param headers:
            Dictionary of custom headers to send, such as User-Agent,
            If-None-Match, etc. If None, pool headers are used. If provided,
            these headers completely replace any pool-specific headers.

        :param retries:
            Configure the number of retries to allow before raising a
            :class:`~urllib3.exceptions.MaxRetryError` exception.

            Pass ``None`` to retry until you receive a response. Pass a
            :class:`~urllib3.util.retry.Retry` object for fine-grained control
            over different types of retries.
            Pass an integer number to retry connection errors that many times,
            but no other types of errors. Pass zero to never retry.

            If ``False``, then retries are disabled and any exception is raised
            immediately. Also, instead of raising a MaxRetryError on redirects,
            the redirect response will be returned.

        :type retries: :class:`~urllib3.util.retry.Retry`, False, or an int.

        :param redirect:
            If True, automatically handle redirects (status codes 301, 302,
            303, 307, 308). Each redirect counts as a retry. Disabling retries
            will disable redirect, too.

        :param assert_same_host:
            If ``True``, will make sure that the host of the pool requests is
            consistent else will raise HostChangedError. When ``False``, you can
            use the pool on an HTTP proxy and request foreign hosts.

        :param timeout:
            If specified, overrides the default timeout for this one
            request. It may be a float (in seconds) or an instance of
            :class:`urllib3.util.Timeout`.

        :param pool_timeout:
            If set and the pool is set to block=True, then this method will
            block for ``pool_timeout`` seconds and raise EmptyPoolError if no
            connection is available within the time period.

        :param release_conn:
            If False, then the urlopen call will not release the connection
            back into the pool once a response is received (but will release if
            you read the entire contents of the response such as when
            `preload_content=True`). This is useful if you're not preloading
            the response's content immediately. You will need to call
            ``r.release_conn()`` on the response ``r`` to return the connection
            back into the pool. If None, it takes the value of
            ``response_kw.get('preload_content', True)``.

        :param chunked:
            If True, urllib3 will send the body using chunked transfer
            encoding. Otherwise, urllib3 will send the body using the standard
            content-length form. Defaults to False.

        :param int body_pos:
            Position to seek to in file-like body in the event of a retry or
            redirect. Typically this won't need to be set because urllib3 will
            auto-populate the value when needed.

        :param \\**response_kw:
            Additional parameters are passed to
            :meth:`urllib3.response.HTTPResponse.from_httplib`
        """

        parsed_url = parse_url(url)
        destination_scheme = parsed_url.scheme

        if headers is None:
            headers = self.headers

        if not isinstance(retries, Retry):
            retries = Retry.from_int(retries, redirect=redirect, default=self.retries)

        if release_conn is None:
            release_conn = response_kw.get("preload_content", True)

        # Check host
        if assert_same_host and not self.is_same_host(url):
            raise HostChangedError(self, url, retries)

        # Ensure that the URL we're connecting to is properly encoded
        if url.startswith("/"):
            url = six.ensure_str(_encode_target(url))
        else:
            url = six.ensure_str(parsed_url.url)

        conn = None

        # Track whether `conn` needs to be released before
        # returning/raising/recursing. Update this variable if necessary, and
        # leave `release_conn` constant throughout the function. That way, if
        # the function recurses, the original value of `release_conn` will be
        # passed down into the recursive call, and its value will be respected.
        #
        # See issue #651 [1] for details.
        #
        # [1] <https://github.com/urllib3/urllib3/issues/651>
        release_this_conn = release_conn

        http_tunnel_required = connection_requires_http_tunnel(
            self.proxy, self.proxy_config, destination_scheme
        )

        # Merge the proxy headers. Only done when not using HTTP CONNECT. We
        # have to copy the headers dict so we can safely change it without those
        # changes being reflected in anyone else's copy.
        if not http_tunnel_required:
            headers = headers.copy()
            headers.update(self.proxy_headers)

        # Must keep the exception bound to a separate variable or else Python 3
        # complains about UnboundLocalError.
        err = None

        # Keep track of whether we cleanly exited the except block. This
        # ensures we do proper cleanup in finally.
        clean_exit = False

        # Rewind body position, if needed. Record current position
        # for future rewinds in the event of a redirect/retry.
        body_pos = set_file_position(body, body_pos)

        try:
            # Request a connection from the queue.
            timeout_obj = self._get_timeout(timeout)
            conn = self._get_conn(timeout=pool_timeout)

            conn.timeout = timeout_obj.connect_timeout

            is_new_proxy_conn = self.proxy is not None and not getattr(
                conn, "sock", None
            )
            if is_new_proxy_conn and http_tunnel_required:
                self._prepare_proxy(conn)

            # Make the request on the httplib connection object.
            httplib_response = self._make_request(
                conn,
                method,
                url,
                timeout=timeout_obj,
                body=body,
                headers=headers,
                chunked=chunked,
            )

            # If we're going to release the connection in ``finally:``, then
            # the response doesn't need to know about the connection. Otherwise
            # it will also try to release it and we'll have a double-release
            # mess.
            response_conn = conn if not release_conn else None

            # Pass method to Response for length checking
            response_kw["request_method"] = method

            # Import httplib's response into our own wrapper object
            response = self.ResponseCls.from_httplib(
                httplib_response,
                pool=self,
                connection=response_conn,
                retries=retries,
                **response_kw
            )

            # Everything went great!
            clean_exit = True

        except EmptyPoolError:
            # Didn't get a connection from the pool, no need to clean up
            clean_exit = True
            release_this_conn = False
            raise

        except (
            TimeoutError,
            HTTPException,
            SocketError,
            ProtocolError,
            BaseSSLError,
            SSLError,
            CertificateError,
        ) as e:
            # Discard the connection for these exceptions. It will be
            # replaced during the next _get_conn() call.
            clean_exit = False

            def _is_ssl_error_message_from_http_proxy(ssl_error):
                # We're trying to detect the message 'WRONG_VERSION_NUMBER' but
                # SSLErrors are kinda all over the place when it comes to the message,
                # so we try to cover our bases here!
                message = " ".join(re.split("[^a-z]", str(ssl_error).lower()))
                return (
                    "wrong version number" in message or "unknown protocol" in message
                )

            # Try to detect a common user error with proxies which is to
            # set an HTTP proxy to be HTTPS when it should be 'http://'
            # (ie {'http': 'http://proxy', 'https': 'https://proxy'})
            # Instead we add a nice error message and point to a URL.
            if (
                isinstance(e, BaseSSLError)
                and self.proxy
                and _is_ssl_error_message_from_http_proxy(e)
                and conn.proxy
                and conn.proxy.scheme == "https"
            ):
                e = ProxyError(
                    "Your proxy appears to only use HTTP and not HTTPS, "
                    "try changing your proxy URL to be HTTP. See: "
                    "https://urllib3.readthedocs.io/en/1.26.x/advanced-usage.html"
                    "#https-proxy-error-http-proxy",
                    SSLError(e),
                )
            elif isinstance(e, (BaseSSLError, CertificateError)):
                e = SSLError(e)
            elif isinstance(e, (SocketError, NewConnectionError)) and self.proxy:
                e = ProxyError("Cannot connect to proxy.", e)
            elif isinstance(e, (SocketError, HTTPException)):
                e = ProtocolError("Connection aborted.", e)

            retries = retries.increment(
                method, url, error=e, _pool=self, _stacktrace=sys.exc_info()[2]
            )
            retries.sleep()

            # Keep track of the error for the retry warning.
            err = e

        finally:
            if not clean_exit:
                # We hit some kind of exception, handled or otherwise. We need
                # to throw the connection away unless explicitly told not to.
                # Close the connection, set the variable to None, and make sure
                # we put the None back in the pool to avoid leaking it.
                conn = conn and conn.close()
                release_this_conn = True

            if release_this_conn:
                # Put the connection back to be reused. If the connection is
                # expired then it will be None, which will get replaced with a
                # fresh connection during _get_conn.
                self._put_conn(conn)

        if not conn:
            # Try again
            log.warning(
                "Retrying (%r) after connection broken by '%r': %s", retries, err, url
            )
            return self.urlopen(
                method,
                url,
                body,
                headers,
                retries,
                redirect,
                assert_same_host,
                timeout=timeout,
                pool_timeout=pool_timeout,
                release_conn=release_conn,
                chunked=chunked,
                body_pos=body_pos,
                **response_kw
            )

        # Handle redirect?
        redirect_location = redirect and response.get_redirect_location()
        if redirect_location:
            if response.status == 303:
                method = "GET"

            try:
                retries = retries.increment(method, url, response=response, _pool=self)
            except MaxRetryError:
                if retries.raise_on_redirect:
                    response.drain_conn()
                    raise
                return response

            response.drain_conn()
            retries.sleep_for_retry(response)
            log.debug("Redirecting %s -> %s", url, redirect_location)
            return self.urlopen(
                method,
                redirect_location,
                body,
                headers,
                retries=retries,
                redirect=redirect,
                assert_same_host=assert_same_host,
                timeout=timeout,
                pool_timeout=pool_timeout,
                release_conn=release_conn,
                chunked=chunked,
                body_pos=body_pos,
                **response_kw
            )

        # Check if we should retry the HTTP response.
        has_retry_after = bool(response.headers.get("Retry-After"))
        if retries.is_retry(method, response.status, has_retry_after):
            try:
                retries = retries.increment(method, url, response=response, _pool=self)
            except MaxRetryError:
                if retries.raise_on_status:
                    response.drain_conn()
                    raise
                return response

            response.drain_conn()
            retries.sleep(response)
            log.debug("Retry: %s", url)
            return self.urlopen(
                method,
                url,
                body,
                headers,
                retries=retries,
                redirect=redirect,
                assert_same_host=assert_same_host,
                timeout=timeout,
                pool_timeout=pool_timeout,
                release_conn=release_conn,
                chunked=chunked,
                body_pos=body_pos,
                **response_kw
            )

        return response

        Get a connection from the pool and perform an HTTP request. This is the
        lowest level call for making a request, so you'll need to specify all
        the raw details.

        .. note::

           More commonly, it's appropriate to use a convenience method provided
           by :class:`.RequestMethods`, such as :meth:`request`.

        .. note::

           `release_conn` will only behave as expected if
           `preload_content=False` because we want to make
           `preload_content=False` the default behaviour someday soon without
           breaking backwards compatibility.

        :param method:
            HTTP request method (such as GET, POST, PUT, etc.)

        :param url:
            The URL to perform the request on.

        :param body:
            Data to send in the request body, either :class:`str`, :class:`bytes`,
            an iterable of :class:`str`/:class:`bytes`, or a file-like object.

        :param headers:
            Dictionary of custom headers to send, such as User-Agent,
            If-None-Match, etc. If None, pool headers are used. If provided,
            these headers completely replace any pool-specific headers.

        :param retries:
            Configure the number of retries to allow before raising a
            :class:`~urllib3.exceptions.MaxRetryError` exception.

            Pass ``None`` to retry until you receive a response. Pass a
            :class:`~urllib3.util.retry.Retry` object for fine-grained control
            over different types of retries.
            Pass an integer number to retry connection errors that many times,
            but no other types of errors. Pass zero to never retry.

            If ``False``, then retries are disabled and any exception is raised
            immediately. Also, instead of raising a MaxRetryError on redirects,
            the redirect response will be returned.

        :type retries: :class:`~urllib3.util.retry.Retry`, False, or an int.

        :param redirect:
            If True, automatically handle redirects (status codes 301, 302,
            303, 307, 308). Each redirect counts as a retry. Disabling retries
            will disable redirect, too.

        :param assert_same_host:
            If ``True``, will make sure that the host of the pool requests is
            consistent else will raise HostChangedError. When ``False``, you can
            use the pool on an HTTP proxy and request foreign hosts.

        :param timeout:
            If specified, overrides the default timeout for this one
            request. It may be a float (in seconds) or an instance of
            :class:`urllib3.util.Timeout`.

        :param pool_timeout:
            If set and the pool is set to block=True, then this method will
            block for ``pool_timeout`` seconds and raise EmptyPoolError if no
            connection is available within the time period.

        :param release_conn:
            If False, then the urlopen call will not release the connection
            back into the pool once a response is received (but will release if
            you read the entire contents of the response such as when
            `preload_content=True`). This is useful if you're not preloading
            the response's content immediately. You will need to call
            ``r.release_conn()`` on the response ``r`` to return the connection
            back into the pool. If None, it takes the value of
            ``response_kw.get('preload_content', True)``.

        :param chunked:
            If True, urllib3 will send the body using chunked transfer
            encoding. Otherwise, urllib3 will send the body using the standard
            content-length form. Defaults to False.

        :param int body_pos:
            Position to seek to in file-like body in the event of a retry or
            redirect. Typically this won't need to be set because urllib3 will
            auto-populate the value when needed.

        :param \**response_kw:
            Additional parameters are passed to
            :meth:`urllib3.response.HTTPResponse.from_httplib`
        
lib/urllib3/connectionpool.py