Look for dead components (weight=0) and remove them
        if enabled by ``kill``.
        Resize storage. Recompute determinant and covariance.

def _cleanup(self, kill, verbose):
        """Look for dead components (weight=0) and remove them
        if enabled by ``kill``.
        Resize storage. Recompute determinant and covariance.

        """
        if kill:
            removed_indices = self.g.prune()

            self.nout -= len(removed_indices)

            if verbose and removed_indices:
                print('Removing %s' % removed_indices)

            for j in removed_indices:
                self.inv_map.pop(j[0])