<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def _get_device_group(self, device):
        '''Get the device group through a device.

        :param device: bigip object -- device
        :returns: tm.cm.device_groups.device_group object
        '''

        return device.tm.cm.device_groups.device_group.load(
            name=self.name, partition=self.partition
        )