@Override
    public Integer call() throws Exception {
        new CommandLine(this).usage(System.out);
        return ToolConstants.INVALID_INPUT_ERROR_CODE;
    }
This class executes 'hyscale generate service' command
It is a sub-command of the 'hyscale generate' command
@see HyscaleGenerateCommand
Every command/sub-command has to implement the {@link Callable} so that
whenever the command is executed the {@link #call()}
method will be invoked

The sub-commands of are handled by @Command annotation
workflow-controller/controller-service/src/main/java/io/hyscale/controller/commands/generate/HyscaleGenerateServiceCommand.java