export default class VisComponent {
  constructor (el) {
    if (!el) {
      throw new Error('"el" is a required argument');
    }

    this.el = el;
  }

  render () {
    throw new Error('"render() is pure abstract"');
  }

  getSerializationFormats () {
    return [];
  }
}

export default class VisComponent {
  constructor (el) {
    if (!el) {
      throw new Error('"el" is a required argument');
    }

    this.el = el;
  }

  render () {
    throw new Error('"render() is pure abstract"');
  }
}

--- 
+++ 
@@ -10,4 +10,8 @@
   render () {
     throw new Error('"render() is pure abstract"');
   }
+
+  getSerializationFormats () {
+    return [];
+  }
 }
Add default getSerializationFormats method in superclass
