'Associate the alert policy to servers
:param clc: the clc-sdk instance to use
:param module: the AnsibleModule object
:param servers: List of servers to add alert policy to
:return: failed_servers: the list of servers which failed while associating alert policy'

@staticmethod
def _add_alert_policy_to_servers(clc, module, servers):

    failed_servers = []
    p = module.params
    alert_policy_id = p.get('alert_policy_id')
    alias = p.get('alias')
    if (alert_policy_id and (not module.check_mode)):
        for server in servers:
            try:
                ClcServer._add_alert_policy_to_server(clc=clc, alias=alias, server_id=server.id, alert_policy_id=alert_policy_id)
            except CLCException:
                failed_servers.append(server)
    return failed_servers
