anchor.diff:    mruby_to_native_ref* box = (mruby_to_native_ref*)malloc(sizeof(mruby_to_native_ref));
     box->belongs_to_ruby = TRUE;
     box->obj = unboxed;
  -  mrb_data_init(obj, box, &<%= klass['name'] %>_data_type);
  +  mrb_data_init(obj, box, &<%= klass['name'].type_to_identifier %>_data_type);
   }
   
   <%= klass['name'] %> *
  
positive.code:   mruby_to_native_ref* box = (mruby_to_native_ref*)malloc(sizeof(mruby_to_native_ref));
    box->belongs_to_ruby = FALSE;
    box->obj = unboxed;
    mrb_data_init(obj, box, &<%= klass['name'] %>_data_type);
  }
  
  void
  
negative.code:  * Boxing implementation for <%= klass['name'] %>
   */
  
  static void free_<%= klass['name'].type_to_identifier %>(mrb_state* mrb, void* ptr) {
    mruby_to_native_ref* box = (mruby_to_native_ref*)ptr;
    if (box->belongs_to_ruby) {
      /* TODO: free is the default. Should be changed if a type-specific
  