Get service assets

<Array|Object|null> getAssets([<String> serviceType])

Returns:

• null if assets for given serviceType not found

• array if assets for given serviceType are found

• object each element of which is an array of service assets if serviceType is provided

Output(service type is empty)

[
    {
        "name": "js asset",
        "data": "http://example.com/asset.js",
        "autoload": "js"
    },
    {
        "name": "css asset",
        "data": "http://example.com/asset.css",
        "autoload": "css"
    }
]

Output(service type is not empty)

{
    "service1": [
        {
            "name": "js asset",
            "data": "http://example.com/service1/asset.js",
            "autoload": "js"
        },
        {
            "name": "css asset",
            "data": "http://example.com/service1/asset.css",
            "autoload": "css"
        }
    ],
    "service2": [
        {
            "name": "js asset",
            "data": "http://example.com/service2/asset.js",
            "autoload": "js"
        },
        {
            "name": "css asset",
            "data": "http://example.com/service2/asset.css",
            "autoload": "css"
        }
    ]
}