internal Displayable(Object o1, Object o2, Object o3, DisplayableType t)
 {
     arg1    = o1;
     arg2    = o2;
     argtype = o3;
     type    = t;
 }
 internal bool supportsOperation(DisplayableType dt)
 {
     return(((int)dt & this.SupportedOperations) != 0);
 }