code: public OvhLoadBalancingTask loadBalancing_serviceName_backend_backend_backupState_POST(String serviceName, String backend, Boolean backupStateSet, String mainBackendIp) throws IOException {
  		String qPath = "/ip/loadBalancing/{serviceName}/backend/{backend}/backupState";
  		StringBuilder sb = path(qPath, serviceName, backend);
  		HashMap<String, Object>o = new HashMap<String, Object>();
  		addBody(o, "backupStateSet", backupStateSet);
  		addBody(o, "mainBackendIp", mainBackendIp);
  		String resp = exec(qPath, "POST", sb.toString(), o);
  		return convertTo(resp, OvhLoadBalancingTask.class);
  	}
docs: Set or unset the backend as a backup of another backend. Requests will be directed to the backup only if the main backend is in probe fail
  
  REST: POST /ip/loadBalancing/{serviceName}/backend/{backend}/backupState
  @param backupStateSet [required] Set or unset the backend as backup. mainBackendIp is optional in case of unset
  @param mainBackendIp [required] Main backend ip, must be in the same zone as the backup
  @param serviceName [required] The internal name of your IP load balancing
  @param backend [required] IP of your backend