On the authority of Hackett v. People, 158 Colo. 304, 406 P.2d 331, the trial court summarily denied Stanley R. Hookers motion for post conviction relief [Crim. P. 35(b)] from a penitentiary sentence fully served. Hackett holds that 35(b) relief is unavailable to a petitioner who is not in custody under sentence pursuant to a conviction which he seeks to vacate.