Tests for the existence of a key within the map. 
   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
- key
-  Type:  System String  
 The key to be searched for.