private static boolean isSingleType(final String[] parameter) {
        return parameter.length == 1 && isSingleType(parameter[0]);
    }
only one parameter which is customized type.

@param parameter parameter array.
@return only one parameter and it's customized type return true otherwise return false.
shenyu-plugin/shenyu-plugin-proxy/shenyu-plugin-rpc/shenyu-plugin-sofa/src/main/java/org/apache/shenyu/plugin/sofa/param/SofaParamResolveServiceImpl.java