text: //// [chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.ts]
  class Chain<T extends A> {
      constructor(public value: T) { }
      then<S extends T>(cb: (x: T) => S): Chain<S> {
          return null;
      }
  }
  
  class A {
      x;
  }
  class B extends A {
      y;
  }
  class C extends B {
      z;
  }
  
  // Ok to go down the chain, but error to try to climb back up
  (new Chain(new A)).then(a => new B).then(b => new C).then(c => new B).then(b => new A);
  
  //// [chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js]
  var __extends = (this && this.__extends) || function (d, b) {
      for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
      function __() { this.constructor = d; }
      d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
  };
  var Chain = (function () {
      function Chain(value) {
          this.value = value;
      }
      Chain.prototype.then = function (cb) {
          return null;
      };
      return Chain;
  })();
  var A = (function () {
      function A() {
      }
      return A;
  })();
  var B = (function (_super) {
      __extends(B, _super);
      function B() {
          _super.apply(this, arguments);
      }
      return B;
  })(A);
  var C = (function (_super) {
      __extends(C, _super);
      function C() {
          _super.apply(this, arguments);
      }
      return C;
  })(B);
  // Ok to go down the chain, but error to try to climb back up
  (new Chain(new A)).then(function (a) { return new B; }).then(function (b) { return new C; }).then(function (c) { return new B; }).then(function (b) { return new A; });
  