The restriction, however, does not prevent the State from commenting upon the uncontradicted nature of the evidence even though the defendant is the only person in a position to contradict the State's evidence. ( People v. Hopkins (1972), 52 Ill.2d 1, 284 N.E.2d 283; People v. Jackson (1978), 56 Ill. App.3d 1059, 372 N.E.2d 970.) The test to be applied in determining whether the prosecutor's argument falls within the prohibited area of comment is whether "the reference [was] intended or calculated to direct the attention of the jury to the defendant's neglect to avail himself of his legal right to testify."