def _raise_timeout(
        self,
        err: BaseSSLError | OSError | SocketTimeout,
        url: str,
        timeout_value: _TYPE_TIMEOUT | None,
    ) -> None:
        """Is the error actually a timeout? Will raise a ReadTimeout or pass"""

        if isinstance(err, SocketTimeout):
            raise ReadTimeoutError(
                self, url, f"Read timed out. (read timeout={timeout_value})"
            ) from err

        # See the above comment about EAGAIN in Python 3.
        if hasattr(err, "errno") and err.errno in _blocking_errnos:
            raise ReadTimeoutError(
                self, url, f"Read timed out. (read timeout={timeout_value})"
            ) from err
Is the error actually a timeout? Will raise a ReadTimeout or pass
src/urllib3/connectionpool.py