protected String getProtocol() {
        switch (protocol) {
            case HTTP : return "http";
            case HTTPS : return "https";
            default : throw new UnsupportedOperationException(
                String.format("Unknown enum constant '%s'.", protocol)
            );
        }
    }
Default implementation of the {@link Rest}-interface.

@author  Emil Forslund
@since   1.0.0
common-parent/rest/src/main/java/com/speedment/common/rest/RestImpl.java