text: //// [classIndexer4.ts]
  class C123 {
      [s: string]: number;
      constructor() {
      }
  }
  
  interface D123 extends C123 {
      x: number;
      y: string;
  }
  
  //// [classIndexer4.js]
  var C123 = (function () {
      function C123() {
      }
      return C123;
  }());
  