app.compose(function() {
    var should = app.get('should')
    app.set('calc', {

        numberOfBits: function (num) {
            should.bePositiveInteger(num);
            return Math.floor(Math.log(num) / Math.log(2)) + 1;
        },

        maxNumberOfBits: function (arr) {

            var counts = [], num;
            for (var i = 0; i < arr.length; i++) {
                num = arr[i];
                counts.push(this.numberOfBits(num));
            }

            return Math.max.apply(null, counts);
        }
    });

});