text: import { html, css, LitElement } from 'lit-element';
  
  export class TestElement extends LitElement {
    static get styles() {
      return css`
        :host {
          display: block;
          padding: 25px;
        }
      `;
    }
  
    static get properties() {
      return {
        title: { type: String },
        counter: { type: Number },
      };
    }
  
    constructor() {
      super();
      this.title = 'Hey there';
      this.counter = 5;
    }
  
    __increment() {
      this.counter += 1;
    }
  
    render() {
      return html`
        <h2 id="title"> ${this.title} Nr. ${this.counter}!</h2>
        <button @click=${this.__increment}>increment</button>
      `;
    }
  }
  
  window.customElements.define('test-element', TestElement);