namespace MainApp {
    /**
     * Square
     */
    export class Square {
        constructor() {
        }
    }
}

/// <reference path="./interfaces/puttable.ts" />

namespace MainApp {
    /**
     * Square
     */
    export class Square {
        constructor(public piece:Puttable = null) {
        }
    }
}

Add piece property to Square
Add piece property to Square
