@Override
    public Integer call() throws Exception {
        if (!CommandUtil.isInputValid(this)) {
            return ToolConstants.INVALID_INPUT_ERROR_CODE;
        }
        WorkflowContext context = new WorkflowContextBuilder(appName)
                .withNamespace(namespace).withServiceName(serviceName).withAuthConfig(authConfigBuilder.getAuthConfig()).get();
        if (!clusterValidator.validate(context)) {
            WorkflowLogger.logPersistedActivities();
            return ToolConstants.INVALID_INPUT_ERROR_CODE;
        }

        WorkflowLogger.header(ControllerActivity.SERVICE_NAME, serviceName);

        List<ReplicaInfo> replicas = replicaProcessingService.getReplicas(appName, serviceName, namespace, true);
        if (replicas != null && !replicas.isEmpty()) {
            replicaProcessingService.logReplicas(replicas, false);
        } else if (replicaProcessingService.hasService(context.getAuthConfig(), appName, serviceName, namespace)){
            WorkflowLogger.error(DeployerActivity.SERVICE_WITH_ZERO_REPLICAS);
            WorkflowLogger.footer();
        } else {
            WorkflowLogger.error(ControllerActivity.SERVICE_NOT_CREATED);
            WorkflowLogger.error(ControllerActivity.CHECK_SERVICE_STATUS);
            WorkflowLogger.footer();
        }

        return ToolConstants.HYSCALE_SUCCESS_CODE;
    }
This class executes 'hyscale get replica status' command.
It is a sub-command of the 'hyscale get replica' command

Options:
    service - service name
 namespace - namespace in which the app is deployed
 appName - name of the app
<p>
Eg: hyscale get replica status -s s1 -n dev -a sample
<p>
Fetches the replica status of a service from the given cluster.
The replica status has been abstracted over the pod status,see {@link DeploymentStatus},
gives the information about service and the failure message when it is in
NotRunning status.
@see HyscaleGetReplicaCommand .
Every command/sub-command has to implement the {@link Callable} so that
whenever the command is executed the {@link #call()}
method will be invoked
workflow-controller/controller-service/src/main/java/io/hyscale/controller/commands/get/replica/HyscaleReplicaStatusCommand.java