How to use the blinker._utilities.lazy_property function in blinker

    @lazy_property
    def receiver_disconnected(self):
        """Emitted after :meth:`disconnect`.

        The sender is the signal instance, and the :meth:`disconnect` arguments
        are passed through: *receiver* and *sender*.

        Note, this signal is emitted **only** when :meth:`disconnect` is
        called explicitly.

        The disconnect signal can not be emitted by an automatic disconnect
        (due to a weakly referenced receiver or sender going out of scope),
        as the receiver and/or sender instances are no longer available for
        use at the time this signal would be emitted.

        An alternative approach is available by subscribing to
        :attr:`receiver_connected` and setting up a custom weakref cleanup

    @lazy_property
    def receiver_disconnected(self):
        """Emitted after :meth:`disconnect`.

        The sender is the signal instance, and the :meth:`disconnect` arguments
        are passed through: *receiver* and *sender*.

        Note, this signal is emitted **only** when :meth:`disconnect` is
        called explicitly.

        The disconnect signal can not be emitted by an automatic disconnect
        (due to a weakly referenced receiver or sender going out of scope),
        as the receiver and/or sender instances are no longer available for
        use at the time this signal would be emitted.

        An alternative approach is available by subscribing to
        :attr:`receiver_connected` and setting up a custom weakref cleanup

    @lazy_property
    def receiver_connected(self):
        """Emitted after each :meth:`connect`.

        The signal sender is the signal instance, and the :meth:`connect`
        arguments are passed through: *receiver*, *sender*, and *weak*.

        .. versionadded:: 1.2

        """
        return Signal(doc="Emitted after a receiver connects.")

    @lazy_property
    def receiver_disconnected(self):
        """Emitted after :meth:`disconnect`.

        The sender is the signal instance, and the :meth:`disconnect` arguments
        are passed through: *receiver* and *sender*.

        Note, this signal is emitted **only** when :meth:`disconnect` is
        called explicitly.

        The disconnect signal can not be emitted by an automatic disconnect
        (due to a weakly referenced receiver or sender going out of scope),
        as the receiver and/or sender instances are no longer available for
        use at the time this signal would be emitted.

        An alternative approach is available by subscribing to
        :attr:`receiver_connected` and setting up a custom weakref cleanup

    @lazy_property
    def receiver_connected(self):
        """Emitted after each :meth:`connect`.

        The signal sender is the signal instance, and the :meth:`connect`
        arguments are passed through: *receiver*, *sender*, and *weak*.

        .. versionadded:: 1.2

        """
        return Signal(doc="Emitted after a receiver connects.")

    @lazy_property
    def receiver_connected(self):
        """Emitted after each :meth:`connect`.

        The signal sender is the signal instance, and the :meth:`connect`
        arguments are passed through: *receiver*, *sender*, and *weak*.

        .. versionadded:: 1.2

        """
        return Signal(doc="Emitted after a receiver connects.")

    @lazy_property
    def receiver_disconnected(self):
        """Emitted after :meth:`disconnect`.

        The sender is the signal instance, and the :meth:`disconnect` arguments
        are passed through: *receiver* and *sender*.

        Note, this signal is emitted **only** when :meth:`disconnect` is
        called explicitly.

        The disconnect signal can not be emitted by an automatic disconnect
        (due to a weakly referenced receiver or sender going out of scope),
        as the receiver and/or sender instances are no longer available for
        use at the time this signal would be emitted.

        An alternative approach is available by subscribing to
        :attr:`receiver_connected` and setting up a custom weakref cleanup

    @lazy_property
    def receiver_connected(self):
        """Emitted after each :meth:`connect`.

        The signal sender is the signal instance, and the :meth:`connect`
        arguments are passed through: *receiver*, *sender*, and *weak*.

        .. versionadded:: 1.2

        """
        return Signal(doc="Emitted after a receiver connects.")