anchor.diff:        this.makePort('out:success');
         this.makePort('err:failed');
   
  -      this.port('in:val').forceCondition((n){ return Valids.exist(this.elem); });
  +      this.port('in:val').forceCondition(Elements.elementExist(this.elem));
         this.port('in:val').tap((n){
             if(!this.elem.classes.contains(n.data)) return this.port('err:failed').send(n);
             this.elem.remove(n.data);
  
positive.code: }
  
  class SetDataAttr extends AttrCore{
  
      SetDataAttr(){
        this.meta('id','SetDataAttr');
  
        this.makePort('in:set');
        this.makePort('out:val');
  
        this.port('in:set').forceCondition(Elements.elementExist(this.elem));
        this.port('in:set').forceCondition(Valids.isString);
  
        this.port('in:set').tap((n){
            
        });
  
      }
  
negative.code: 
        this.makePort('in:class');
        
        this.port('in:val').forceCondition(Elements.elementExist(this.elem));
        this.port('in:val').forceCondition(Valids.isString);
        this.port('in:val').tap((n){
          this.elem.classes.add(n.data);
  