'get exist lsa arrival start interval'

def get_exist_lsa_a_start_interval(self):

    if (not self.ospf_info):
        return None
    for ospf_site in self.ospf_info['ospfsite']:
        if (ospf_site['processId'] == self.ospf):
            return ospf_site['lsaArrivalStartInterval']
        else:
            continue
    return None
