I have a simple auth middleware for express. It checks header and if all cool it calls next()

Now when i am in "DoSomething" "this" is equal to global and not the instance of "Test" and
"this.DoSomeThingPrivate" is undefined.

I have tried the 

```
DoSomeThingPrivate :() => void;

this.DoSomeThingPrivate = () => {
...
}

```

pattern. But also does not work.

```
import express = require('express');

var app = express();

class Test {    
    constructor() {        
    }

    DoSomething(req:express.Request, res:express.Response, next:Function) :void {       
        this.DoSomeThingPrivate();
    }

    private DoSomeThingPrivate() :void
    {       
    }
}

var test = new Test();

app.use(test.DoSomething);

```

[Relates to this](https://stackoverflow.com/questions/17263076/the-this-scope-of-nodejs-middlewares-when-using-typescript)

Any Ideas...

thanks