'Instantiates class and passes back application object.
:param host: defaults to CONF.host
:param binary: defaults to basename of executable
:param topic: defaults to bin_name - \'nova-\' part
:param manager: defaults to CONF.<topic>_manager
:param report_interval: defaults to CONF.report_interval
:param periodic_enable: defaults to CONF.periodic_enable
:param periodic_fuzzy_delay: defaults to CONF.periodic_fuzzy_delay
:param periodic_interval_max: if set, the max time to wait between runs'

@classmethod
def create(cls, host=None, binary=None, topic=None, manager=None, report_interval=None, periodic_enable=None, periodic_fuzzy_delay=None, periodic_interval_max=None):

    if (not host):
        host = CONF.host
    if (not binary):
        binary = os.path.basename(sys.argv[0])
    if (not topic):
        topic = binary.rpartition('nova-')[2]
    if (not manager):
        manager = SERVICE_MANAGERS.get(binary)
    if (report_interval is None):
        report_interval = CONF.report_interval
    if (periodic_enable is None):
        periodic_enable = CONF.periodic_enable
    if (periodic_fuzzy_delay is None):
        periodic_fuzzy_delay = CONF.periodic_fuzzy_delay
    debugger.init()
    service_obj = cls(host, binary, topic, manager, report_interval=report_interval, periodic_enable=periodic_enable, periodic_fuzzy_delay=periodic_fuzzy_delay, periodic_interval_max=periodic_interval_max)
    return service_obj
