, Rogers v. United States, 1951, 340 U.S. 367, 71 S.Ct. 438, and to require him to answer if 'it clearly appears to the court that he is mistaken.' Temple v. Commonwealth 1880, 75 Va. 892, 899. However, if the witness, upon interposing his claim, were required to prove the hazard in the sense in which a claim is usually r