@property
def interfaces(self):
    if self._interfaces:  # those are the formatted ones
        return self._interfaces

    if not self._device_interfaces:  # to cache them
        with self.connect():
            self._device_interfaces = self.device.get_interfaces()

    interfaces = {}
    # all the code for mangling the interfaces calling self.optics, etc...
    # if this is getting too large it can be moved to something like
    # def _get_formatted_interfaces(self)

    self._interfaces = interfaces  # or self._get_formatted_interfaces()
    return self._interfaces