code: function(target){
              // skip valid type check if value evaluating to false or empty array.
              if(!this.validTypes || !this.validTypes.length){
                  return true;
              }
  
              for(var i = this.validTypes.length - 1; i >= 0; i--){
                  var type = this.validTypes[i];
                  if(target instanceof type){
                      return true;
                  }
              }
  
              // no valid type match found
              return false;
          }
docs: Checks if a target object is an instance of a type in `this.validTypes`.
  @method checkValidType
  @param {Object} target - The target to be checked.
  @return {Bool} `true` if valid.