text: // @strictNullChecks: true
  // @declaration: true
  function f1(x, y) {
      let obj;
      obj = x;
      obj = y;
  }
  function f2(x, y) {
      let obj;
      obj = x;
      obj = y;
  }
  function f3(x) {
      x = {
      };
  }
  // Repro from #13747
  class Form {
      constructor(){
          this.values = {
          };
      }
  }
  