code: function callStaticMethod(methodName, req, res, next) {
    res.__apiMethod = 'staticMethod';
    res.__apiStaticMethod = methodName;
    var self = this;
    var methodOptions = this.apiOptions.exposeStatic[methodName] || {};
  
    var wrapper = methodOptions.exec;
    if (!(wrapper instanceof Function)) wrapper = null;
  
    var httpMethod = methodOptions.method || 'post';
    var params = (httpMethod !== 'get') ? req.body : req.query;
  
    var mFunc = wrapper || this.model[methodName];
  
    mFunc.call(this.model, params, function(err, result) {
      if (err) return next(err);
      res.json(result);
    });
  }
docs: callStaticMethod - controller that calls a static method of model
  
  @param  {String}           methodName the name of method that should be called
  @param  {express.Request}  req        the http(s) request
  @param  {express.Response} res        the http(s) response
  @param  {Function}         next       the callback should be called if controller fails
  
  @memberof ModelAPIRouter