how to use the module mode in plovr

Question

The plovr works well for single file like this:

{
    id:"main",
    paths:".",
    pretty-print:true,
    inputs:["eval.js","util.js","ui.js"],
    output-wrapper:"\n(function(){%output%}).call(this);\n",
}

As shown in the config,the inputs will be compiled together,and this is the core module in my application.

Then I have some sub modules in the /modules directory.

Now I want compile them together,but I do not know how to config them:

I tried this:

{
    id:"main",
    paths:".",
    pretty-print:true,
    modules:{
        core:{
            inputs:["eval.js","util.js","ui.js"],
            deps:[]
        },
        panel:{
            inputs:["modules/panel.js"],
            deps:"core"         
        }
        window:{
            inputs:["modules/window.js"],
            deps:"core"
        }
    }
}

Then it does not work.

How about the output-wrapper for the core module?

And where does the sub modules compile to?

BTW,this is my application directory:

src
    eval.js
    util.js
    ui.js

    modules
        panel.js
        window.js
    plovr.jar
    plovr-config.js