public override T Dispatch <T>(TypeIsaVisitor <T> visitor)
 {
     return(visitor.VisitDataType(this));
 }
 public override T Dispatch <T>(TypeIsaVisitor <T> visitor)
 {
     return(visitor.VisitPrimitiveType(this));
 }
 public abstract T Dispatch <T>(TypeIsaVisitor <T> visitor);