Access Inbound HTTP Headers in Loopback.io Remote Method

I have a remote method where I'm putting my application logic, as below:

module.exports = function(Entity) {
  HcpEntity.retrieveProfile = function(body, cb) {
    process.nextTick(function() {
      //TODO: Application Logic
    }
 }
}

And the corresponding model JSON snippet is:

{
    "name": "HcpEntity",
    "base": "Model",
    "properties": {},
    "methods": {
        "retrieveProfile": {
            "isStatic" : true,
            "accepts": [
                {
                    "arg": "Request",
                    "type": "object",
                    "required": true,
                    "http": {
                        "source": "body"
                    }
                }
            ],
            "returns": {
                "arg": "Response",
                "type": "object"
            },
            "http": {
                "verb": "post"
            }
        }
    }
}

I need to be able to access the incoming HTTP headers in the area marked as //TODO: Application Logic so as to validate them. Could someone please help.