Identifies the number of bars in rebar set. For the current implementation of RebarInSystem, this property will always return the same number as NumberOfBarPositions, since the first and last bars of a RebarInSystem set cannot be suppressed. However, it is included in the RebarInSystem interface for consistency with the Rebar class. 
   Namespace:   Autodesk.Revit.DB.Structure  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2013 
Syntax
Remarks
 Quantity is equal to NumberOfBarPositions if IncludeFirstBar and IncludeLastBar are set. If any end bars are excluded, they are not counted in the Quantity.