text: //// [contextualTypingOfObjectLiterals.ts]
  var obj1: { [x: string]: string; };
  var obj2 = {x: ""};
  obj1 = {}; // Ok
  obj1 = obj2; // Error - indexer doesn't match
  
  function f(x: { [s: string]: string }) { }
  
  f({}); // Ok
  f(obj1); // Ok
  f(obj2); // Error - indexer doesn't match
  
  //// [contextualTypingOfObjectLiterals.js]
  var obj1;
  var obj2 = { x: "" };
  obj1 = {}; // Ok
  obj1 = obj2; // Error - indexer doesn't match
  function f(x) { }
  f({}); // Ok
  f(obj1); // Ok
  f(obj2); // Error - indexer doesn't match
  