it('should set value with setAt', function () {
                this.instance.setAt(0, 1, {red: 1, green: 2, blue: 3, alpha: 4});
                expect(this.blob[8]).to.be.equal(1);
                expect(this.blob[9]).to.be.equal(2);
                expect(this.blob[10]).to.be.equal(3);