code: public static DZcsn cs_ndone (DZcsn N, DZcs C, int[] w, DZcsa x, boolean ok)
  	{
  	//	    cs_spfree (C) ;                     /* free temporary matrix */
  	//	    cs_free (w) ;                       /* free workspace */
  	//	    cs_free (x) ;
  		return (ok ? N : null) ;    /* return result if OK, else free it */
  	}
docs: /* free workspace and return a numeric factorization (Cholesky, LU, or QR)