anchor.diff:  #  A class which does it's own construction but checks nothing
   #
   class BasicPerson ()
  -
       def .new (name age)
         (tag .self (dict))
           define .name name
  
positive.code: assert
     and
       is-instance? fred PersonModern
       equal? (fred.age) 23
  
negative.code:    and
       is-instance? ((BasicPerson.new) "w" 2) BasicPerson
       equal? 2
         (BasicPerson (.new "w" 2)) .age
  #
  #  A class which uses the .new in Object, and adds type checking
  #
  class PersonTraditional (Object)
     def .init((name=String) (age = Bignum))
        define .name name
        define .age age
  
  
  class PersonModern ()
     def .valid?(obj)
        is? obj!name String
        is? obj!age Bignum
     def .new(name age)
        (dict)                             # create the object
           define .name name               # add the data
  