private static TrustManagerImpl toConscrypt(TrustManager trustManager) {
        if (!isConscrypt(trustManager)) {
            throw new IllegalArgumentException(
                "Not a Conscrypt trust manager: " + trustManager.getClass().getName());
        }
        return (TrustManagerImpl) trustManager;
    }
Indicates whether the given {@link TrustManager} was created by this distribution of
Conscrypt.
common/src/main/java/org/conscrypt/Conscrypt.java