What is the current state of the mootness doctrine in Canada?

19. [19] In Borowski v. Canada, supra, Sopinka J. provided what has become in Canada, the classic analysis of the mootness doctrine and the approach to employ in deciding whether to hear a moot appeal. He described the underlying determination in deciding whether to hear a moot appeal at p. 13: In formulating guidelines for the exercise of discretion in departing from a usual practice, it is instructive to examine its underlying rationalia. To the extent that a particular foundation for the practice is either absent or its presence tenuous, the reason for its enforcement disappears or diminishes.