'retrieves the anti affinity policy id of the server based on the CLC server id
:param clc: the clc-sdk instance to use
:param module: the AnsibleModule object
:param alias: the CLC account alias
:param server_id: the CLC server id
:return: aa_policy_id: The anti affinity policy id'

@staticmethod
def _get_aa_policy_id_of_server(clc, module, alias, server_id):

    aa_policy_id = None
    try:
        result = clc.v2.API.Call(method='GET', url=('servers/%s/%s/antiAffinityPolicy' % (alias, server_id)))
        aa_policy_id = result.get('id')
    except APIFailedResponse as ex:
        if (ex.response_status_code != 404):
            module.fail_json(msg='Unable    to    fetch    anti    affinity    policy    for    server    "{0}".    {1}'.format(server_id, str(ex.response_text)))
    return aa_policy_id
