docs: function updateWithDefaults(controlApis) {
      Object.keys(controlApis).forEach(function (controlName) {
          var spec = controlApis[controlName];
          var winjsControlName = spec.underlyingControlName || controlName;
          spec.winjsControl = spec.winjsControl || WinJS.UI[winjsControlName];
          spec.displayName = spec.displayName || winjsControlName;
          spec.propHandlers = merge(
              defaultPropHandlers, // Common to all WinJS controls
              DefaultControlPropHandlers[winjsControlName], // Control-specific derived from RawControlApis
              spec.propHandlers // Control-specific handwritten
          );
      });
      return controlApis;
  }