'Given an initiator, get its corresponding initiator group, if any.
:param array: the array serial number
:param initiator: the initiator id
:returns: found_init_group_name -- string'

def get_initiator_group_from_initiator(self, array, initiator):

    found_init_group_name = None
    init_details = self.get_initiator(array, initiator)
    if init_details:
        found_init_group_name = init_details.get('host')
    else:
        LOG.error('Unable    to    retrieve    initiator    details    for    %(init)s.', {'init': initiator})
    return found_init_group_name
