Extended debounce function with methods inProgress(), cancel() & applyImmediate()

sozDebouncer.js

var sozDebouncer = function (func, wait) {
    if (typeof func != 'function') {
        throw new TypeError;
    }
    wait = Math.max(parseInt(wait, 10) || 0, 0);
    
    var timer;
    var thisArg;
    var args;
    
    var debouncedFunc = function () {
        thisArg = this;
        args = arguments;
        
        if (timer) {
            clearTimeout(timer);
        }
        timer = setTimeout(function() {
            func.apply(thisArg, args);
            timer = null;
        }, wait)
    };
    debouncedFunc.inProgress = function () {
        return timer ? true : false;
    };
    debouncedFunc.applyImmediate = function () {
        if (this.inProgress()) {
            this.cancel();
            func.apply(thisArg, args);
        }
    };
    debouncedFunc.cancel = function () {
        if (this.inProgress()) {
            clearTimeout(timer);
        }
    };
    return debouncedFunc;
};