This method will be called when commitModification method is called on a subject object retrieved through a SecContext instance.
      Syntax
         
            boolean 
            modifySubject
            (
            Map< String, Object > 
            context
            , 
            
                  SecSubject
                
            subject
            , 
            
                  Attributed
                
            modifiedAttributes
            ) throws SecException
         
      
      Parameters
         
            - 
               context – 
               the context map
            
- 
               subject – 
               the subject to be modified
            
- 
               modifiedAttributes – 
               modified subject attrbutes to be committed
            
Returns
boolean value. "true" indicates subject modification is committed successfully; "false" indicates failed subject modification
      Usage
         Attributer can simply return false if it doesn't support this method.