Insert the specified category into the set. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
| C# | 
|---|
   |  
| Visual Basic | 
|---|
   |  
| Visual C++ | 
|---|
   |  
Parameters
- item
 -  Type:  Autodesk.Revit.DB Category  
The item to be inserted into the set.