What impact would cross-examination have had on the credibility of the witness?

examination would have produced a significantly different impression of the witness's credibility. (Delaware v. Van Arsdall (1986) 475 U.S. 673, 680 [89 L.Ed.2d 674, 684].) Improper denial of cross-examination requires reversal unless the error was harmless beyond a reasonable doubt. (Id. at p. 684 [89 L.Ed.2d at p. 686].) Whether the constitutionally improper exclusion of impeachment evidence is harmless depends on factors including the importance of the witness's testimony in the prosecution's case, whether the testimony was cumulative, the presence or absence of evidence corroborating or contradicting the testimony of the witness on material points, the extent of cross-examination otherwise permitted, and the overall strength of the prosecution's case. (Ibid.)