docs: function PropHandlers_warn(warnMessage) {
          return {
              // Don't need preCtorInit because this prop handler doesn't have any side
              // effects on the WinJS control. update also runs during initialization so
              // update is just as good as preCtorInit for our use case.
              update: function warn_update(winjsComponent, propName, oldValue, newValue) {
                  console.warn(winjsComponent.displayName + ": " + warnMessage);
              }
          };
      }