I have a geodatabase that have more than 100 Line feature classes with different attribute. I want to create a model using Unsplit Line tool with condition all attributes must be tick in Dissolve field except unique attributes ( OBJECTID, Created_User, Created_Date, Last_Edited_User, Last_Edited_Date) . How to iterate all feature in the model builder because all the Lines feature classes have different attribute except OBJECTID, Created_User, Created_Date, Last_Edited_User and Last_Edited_Date?