What is the test for assessing aggravated damages in a libel action?

In Hill, Cory J., at pp.1205 and 1206, addressed the purpose and considerations relevant to an award of aggravated damages: Aggravated damages may be awarded in circumstances where the defendants’ conduct has been particularly high-handed or oppressive, thereby increasing the plaintiff's humiliation and anxiety arising from the libellous statement. The nature of these damages was aptly described by Robbins J.A. in Walker v. C.F.T.O. Ltd., supra, in these words at p. 111: Where the defendant is guilty of insulting, high-handed, spiteful, malicious or oppressive conduct which increases the mental distress — the humiliation, indignation, anxiety, grief, fear and the like — suffered by the plaintiff as a result of being defamed, the plaintiff may be entitled to what has come to be known as "aggravated damages”. These damages take into account the additional harm caused to the plaintiff’s feelings by the defendant's outrageous and malicious conduct. Like general or special damages, they are compensatory in nature. Their assessment requires consideration by the jury of the entire conduct of the defendant prior to the publication of the libel and continuing through to the conclusion of the trial. They represent the expression of natural indignation of right-thinking people arising from the malicious conduct of the defendant. […] There are a number of factors that a jury may properly take into account in assessing aggravated damages. For example, was there a withdrawal of the libellous statement made by the defendants and an apology tendered? If there was, this may go far to establishing that there was no malicious conduct on the part of the defendant warranting an award of aggravated damages. The jury may also consider whether there was a repetition of the libel, conduct that was calculated to deter the plaintiff from proceeding with the libel action, a prolonged and hostile cross-examination of the plaintiff or a plea of justification which the defendant knew was bound to fail.