code: function(prop){
          var props = {},
              len, i = 0, item;
  
          prop = Array.from(prop);
          len = prop.length;
          
          while(len--){
              props[prop[i++]] = void 0;
          }
  
          // void 0 is used because 'undefined' is a var that can be changed in some browsers
          this.set(props);
  
          return this;
      }
docs: Unset a data property. It can not be erased so it will be set to undefined
  
  @param  {String|Array} prop Property name/names to be unset
  @return {Class} The Model instance