I am using Bayesian MCMC estimation methods for GARCH models and I want to check, if model residuals are uncorrelated. In classical frequentist approach, one would use standard Ljung-Box test to check this. But with MCMC estimation, I have 10,000 volatility samples (so 10,000 residuals) for each observation. So is there any sufficient method how to perform some correlation test in Bayesian sense?