'Creates and configures a cluster from this cluster template\'s settings.
create - create new nodes when starting the cluster. set to False to
use existing nodes
create_only - only create the cluster node instances, don\'t configure
the cluster
validate - whether or not to validate the cluster settings used.
False will ignore validate_only and validate_running
keywords and is effectively the same as running _start
validate_only - only validate cluster settings, do not create or
configure cluster
validate_running - whether or not to validate the existing instances
being used against this cluster\'s settings'

def start(self, create=True, create_only=False, validate=True, validate_only=False, validate_running=False):

    if validate:
        validator = self.validator
        if ((not create) and validate_running):
            try:
                validator.validate_running_instances()
            except exception.ClusterValidationError as e:
                msg = 'Existing    nodes    are    not    compatible    with    cluster    '
                msg += 'settings:\n'
                e.msg = (msg + e.msg)
                raise
        validator.validate()
        if validate_only:
            return
    else:
        log.warn('SKIPPING    VALIDATION    -    USE    AT    YOUR    OWN    RISK')
    return self._start(create=create, create_only=create_only)
