code: function permittedOptions(methodName) {
          var options = ghostBookshelf.Model.permittedOptions.call(this, methodName),
  
              // whitelists for the `options` hash argument on methods, by method name.
              // these are the only options that can be passed to Bookshelf / Knex.
              validOptions = {
                  findOne: ['withRelated']
              };
  
          if (validOptions[methodName]) {
              options = options.concat(validOptions[methodName]);
          }
  
          return options;
      }
docs: Returns an array of keys permitted in a method's `options` hash, depending on the current method.
  @param {String} methodName The name of the method to check valid options for.
  @return {Array} Keys allowed in the `options` hash of the model's method.