private static int getProtocolConstant(String protocol) {
        if (protocol.equals(DEPRECATED_PROTOCOL_TLSV1)) {
            return NativeConstants.TLS1_VERSION;
        } else if (protocol.equals(DEPRECATED_PROTOCOL_TLSV1_1)) {
            return NativeConstants.TLS1_1_VERSION;
        } else if (protocol.equals(SUPPORTED_PROTOCOL_TLSV1_2)) {
            return NativeConstants.TLS1_2_VERSION;
        } else if (protocol.equals(SUPPORTED_PROTOCOL_TLSV1_3)) {
            return NativeConstants.TLS1_3_VERSION;
        } else {
            throw new AssertionError("Unknown protocol encountered: " + protocol);
        }
    }
Protocols to enable by default when "TLSv1" is requested.
common/src/main/java/org/conscrypt/NativeCrypto.java