CustomElement with shadow dom

Friends,

   I have created custom element with shadow dom. 

class RamElementE extends HTMLElement {
   static get observedAttributes(){return ["label"];}
   constructor(){ super();
          this.attachShadow({mode:"open"});
          this.input =  document.createElement("input

");this.label =  document.createElement("label");this.input.id="me";
          this.button = document.createElement("button");this.button.textContent="∆";
          this.shadowRoot.appendChild(this.input); this.shadowRoot.appendChild(this.label);this.shadowRoot.appendChild(this.button);
   }
  attributeChangedCallback(name,oldVal,newVal){if(name === 'label' && newVal){this.label.textContent = newVal;this.button.textContent=newVal;}}
}
customElements.define("ram-element-e",RamElementE);