Constructor.
      Syntax
         
             
            TextBoxAttribute
            (
            String 
            id
            , 
            String 
            description
            , 
            boolean 
            optional
            )
         
      
      Parameters
         
            - 
               id – 
               unique id of this state. NOTE: id needs to be unique within the same state
            
 
            - 
               description – 
               detailed description of input attribute, to be displayed on the state editor
            
 
            - 
               optional – 
               True/False for whether the field is optional or not, respectively