static String[] checkEnabledProtocols(String[] protocols) {
        if (protocols == null) {
            throw new IllegalArgumentException("protocols == null");
        }
        for (String protocol : protocols) {
            if (protocol == null) {
                throw new IllegalArgumentException("protocols contains null");
            }
            if (!Arrays.asList(SUPPORTED_PROTOCOLS).contains(protocol)) {
                throw new IllegalArgumentException("protocol " + protocol + " is not supported");
            }
        }
        return protocols;
    }
Protocols to enable by default when "TLSv1" is requested.
common/src/main/java/org/conscrypt/NativeCrypto.java