Additions allow you to add arbitrary C# to the generated classes
before they are compiled.  This can be helpful for providing convenience
methods or adding pure C# classes.

== Adding Methods to Generated Classes ==

Let's say the library being bound has a Rectangle class with a constructor
that takes an x and y position, and a width and length size.  It will look like
this:

public partial class Rectangle
{
    public Rectangle (int x, int y, int width, int height)
    {
        // JNI bindings
    }
}

Imagine we want to add a constructor to this class that takes a Point and
Size structure instead of 4 ints.  We can add a new file called Rectangle.cs
with a partial class containing our new method:

public partial class Rectangle
{
    public Rectangle (Point location, Size size) :
        this (location.X, location.Y, size.Width, size.Height)
    {
    }
}

At compile time, the additions class will be added to the generated class
and the final assembly will a Rectangle class with both constructors.


== Adding C# Classes ==

Another thing that can be done is adding fully C# managed classes to the
generated library.  In the above example, let's assume that there isn't a
Point class available in Java or our library.  The one we create doesn't need
to interact with Java, so we'll create it like a normal class in C#.

By adding a Point.cs file with this class, it will end up in the binding library:

public class Point
{
    public int X { get; set; }
    public int Y { get; set; }
}