code: function exposeSwagger(path, options) {
    if (typeof path !== 'string') {
      options = path;
      path = null;
    }
    path = path || '/swagger.json';
    options = options || {};
    var needCors = options.cors; delete options.cors;
    var beautify = options.beautify; delete options.beautify;
    beautify = beautify === true ? '  ' : beautify;
    this.__swaggerDocURL = path;
    this.__swaggerDocJSON = JSON.stringify(
      this.swaggerDoc(options), null, beautify
    );
    if (needCors !== false) {
      this.get(path, cors(), swaggerJSON.bind(this));
    } else {
      this.get(path, swaggerJSON.bind(this));
    }
    return this;
  }
docs: exposeSwagger   exposes the swagger document. If document is not created
  the method forces model description;
  
  @param {String} [path='/swagger.json']   path to mount swagger document
  @param  {Object} [options]   options for swagger document exposition
  @param  {boolean} [options.cors=true]   should the swagger doc be exposed with CORS
  @param  {String} [options.beautify]    the separator for JSON beautifier
  
  @return {ModelAPIExpress}         the API object