What is the test for timely assertion of a right?

As the United States Supreme Court recognized in United States v. Olano (1993) 507 U.S. 725, 731, 113 S.Ct. 1770, 123 L.Ed.2d 508, " [n]o procedural principle is more familiar ... than that a constitutional right, or a right of any other sort, may be forfeited in criminal as well as civil cases by the failure to make timely assertion of the right before a tribunal having jurisdiction to determine it. " (See In re S.B. (2004) 32 Cal.4th 1287, 1293, 13 Cal.Rptr.3d 786, 90 P.3d 746.) "The purpose of this rule is to encourage parties to bring errors to the attention of the trial court, so that they may be corrected." (Ibid .)