code: function scheduleHandler (p1, p2) {
          return setTimeout(function () {
              var x, handler = p1._s ? p2._onFulfilled : p2._onRejected;
  
              // 2.2.7.3
              // 2.2.7.4
              if (handler === void 0) {
                  settlePromise(p2, p1._s, p1._v);
                  return;
              }
  
              try {
                  // 2.2.5
                  x = handler(p1._v);
              } catch (err) {
                  // 2.2.7.2
                  settlePromise(p2, $rejected, err);
                  return;
              }
  
              // 2.2.7.1
              settleWithX(p2, x);
          });
      }
docs: Resolve the value returned by onFulfilled or onRejected.
  @private
  @param {Yaku} p1
  @param {Yaku} p2