若\(\sin \theta = \frac{{\sqrt 3 }}{3}\)，求\(\frac{{\cos (\pi - \theta )}}{{\cos \theta [\sin (\frac{{3\pi }}{2} - \theta ) - 1]}} + \frac{{\cos (2\pi - \theta )}}{{\cos (\pi + \theta )\sin (\frac{\pi }{2} + \theta ) - \sin (\frac{{3\pi }}{2} + \theta )}}\)的值为 ___．
