In United States v. Owens (1988) 484 U.S. 554 108 S. Ct. 838, 98 L. Ed. 2d 951, the United States Supreme Court adopted Justice Harlan's view. "We agree with the answer suggested 18 years ago by Justice Harlan. 'The Confrontation Clause guarantees only "an opportunity for effective cross-examination, not cross-examination that is effective in whatever way, and to whatever extent, the defense might wish." (Id. at p. 559 108 S. Ct. at p. 842.) "The weapons available to impugn the witness' statement when memory loss is asserted will of course not always achieve success, but successful cross-examination is not the constitutional guarantee." (Id. at p. 560 108 S. Ct. at p. 843.) When the declarant "is present at trial and subject to unrestricted cross-examination, "the traditional protections of the oath, cross-examination, and the opportunity for the jury to observe the witness' demeanor satisfy the constitutional requirements." (Ibid.) Owens was anticipated in California by People v. O'Quinn, 109 Cal. App. 3d 219, 226-228, which concluded there was no violation of the constitutional right to confrontation when, "although the witness was ostensibly unable to remember the circumstances of the crime or her statements to the police, she was nevertheless on the stand and available for cross-examination." (Id. at p. 228.) Owens has been followed by the California Supreme Court. (People v. Cummings (1993) 4 Cal. 4th 1233, 1292, fn. 32 18 Cal. Rptr. 2d 796, 850 P.2d 1 also applying its rationale to the confrontation clause in the California Constitution.)