What is the purpose of fetch.json file inside cordova plugins folder?

File fetch.json created inside plugins folder after cordova plugin add executed first time. This file also modified each time I add/remove plugins.

What purpose of this file exactly?
What tools use this file, when and why?
Is there a way to restore plugins using fetch.json (try not to place plugins into repositiory)?
Where can I find some docs about content of this file?

Content of fetch.json:

{
    "com.phonegap.plugins.PushPlugin": {
        "source": {
            "type": "git",
            "url": "https://github.com/phonegap-build/PushPlugin.git",
            "subdir": "."
        },
        "is_top_level": true,
        "variables": {}
    },
    "cordova-plugin-file": {
        "source": {
            "type": "registry",
            "id": "cordova-plugin-file"
        },
        "is_top_level": true,
        "variables": {}
    }
}

Looks like this file tracks installed plugins, their origin and revision, like npm package.json dependencies does, but for plugman. I guess and hope this should migrate to the npm standard soon.

This file is updated on cordova add/remove plugins (https://github.com/apache/cordova-lib/blob/e4e5904619bab05705d62bce92a4c4cd0d45bb82/cordova-lib/src/cordova/plugin.js#L272)

When we cordova prepare, cordova reads plugin list from plugins/ios.json (for ios), then, for each one :