Return the current mission time for the specified instance.

        :rtype: ~datetime.datetime

def get_time(self, instance):
        """
        Return the current mission time for the specified instance.

        :rtype: ~datetime.datetime
        """
        url = '/instances/{}'.format(instance)
        response = self.get_proto(url)
        message = yamcsManagement_pb2.YamcsInstance()
        message.ParseFromString(response.content)
        if message.HasField('missionTime'):
            return parse_isostring(message.missionTime)
        return None