t specified, then
        defaults are loaded from ``HTTPConnection.default_socket_options`` which includes disabling
        Nagle's algorithm (sets TCP_NODELAY to 1) unless the connection is behind a proxy.

        For example, if you wish to enable TCP Keep Alive in addition to the defaults,
        you might pass::

            HTTPConnection.default_socket_options + [
                (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
            ]

        Or you may want to disable the defaults by passing an empty list (e.g., ``[]``).
    r