code: function reformatProperty(next) {
      const self = this;
      paths.forEach(function(path) {
        try {
          const splitted = path.path.split('.');
          const key      = splitted.shift();
          const value    = determineValue(splitted, self[key]);
  
          self[key]      = nest(splitted, value);
        } catch (error) { return next(error); }
      });
  
      next();
    }
docs: If a document is modified, this method will locate the value before save/validation and assign it to the
  appropriate property, allowing for proper validations later.
  @param <Function>: next - function that notifies mongoose this middleware is complete