def log_likelihood(self,x, K_extra=1):
        """
        Estimate the log likelihood with samples from
         the model. Draw k_extra components which were not populated by
         the current model in order to create a truncated approximate
         mixture model.
        """
        x = np.asarray(x)
        ks = self._get_occupied()
        K = len(ks)
        K_total = K + K_extra

        # Sample observation distributions given current labels
        obs_distns = []
        for k in range(K):
            o = copy.deepcopy(self.obs_distn)
            o.resample(data=self._get_data_withlabel(k))
            obs_distns.append(o)

        # Sample extra observation distributions from prior
        for k in range(K_extra):
            o = copy.deepcopy(self.obs_distn)
            o.resample()
            obs_distns.append(o)

        # Sample a set of weights
        weights = Categorical(alpha_0=self.alpha_0,
                              K=K_total,
                              weights=None)

        assert len(self.labels_list) == 1
        weights.resample(data=self.labels_list[0].z)

        # Now compute the log likelihood
        vals = np.empty((x.shape[0],K_total))
        for k in range(K_total):
            vals[:,k] = obs_distns[k].log_likelihood(x)

        vals += weights.log_likelihood(np.arange(K_total))
        assert not np.isnan(vals).any()
        return logsumexp(vals,axis=1).sum()
Estimate the log likelihood with samples from
         the model. Draw k_extra components which were not populated by
         the current model in order to create a truncated approximate
         mixture model.