What is the test for overturning findings of fact following a hearing on a motion to suppress?

The district court's findings of fact following a hearing on a motion to suppress must be upheld unless they are clearly erroneous. See, e.g., United States v. Koskerides, 877 F.2d at 1131; United States v. Isom, 588 F.2d 858, 862 (2d Cir.1978) (defendant's understanding of Miranda warnings). Assessments of the credibility of witnesses are the province of the district court and we are not entitled to overturn those assessments. See, Anderson v. Bessemer City, 470 U.S. at 574, 105 S.Ct. at 1511-12. Where there are two permissible views of the evidence, the court's choice between them cannot be deemed clearly erroneous. Id.