private static Range getProtocolRange(String[] protocols) {
        // TLS protocol negotiation only allows a min and max version
        // to be set, despite the Java API allowing a sparse set of
        // protocols to be enabled.  Use the lowest contiguous range
        // of protocols provided by the caller, which is what we've
        // done historically.
        List<String> protocolsList = Arrays.asList(protocols);
        String min = null;
        String max = null;
        for (int i = 0; i < SUPPORTED_PROTOCOLS.length; i++) {
            String protocol = SUPPORTED_PROTOCOLS[i];
            if (protocolsList.contains(protocol)) {
                if (min == null) {
                    min = protocol;
                }
                max = protocol;
            } else if (min != null) {
                break;
            }
        }
        if ((min == null) || (max == null)) {
            throw new IllegalArgumentException("No protocols enabled.");
        }
        return new Range(min, max);
    }
Protocols to enable by default when "TLSv1" is requested.
common/src/main/java/org/conscrypt/NativeCrypto.java