code: function addGetterSetter(bindingHandlersObject) {
    Object.defineProperties(bindingHandlersObject, {
      'set': {
        configurable: true,
        value: function setBindingHandler(nameOrObject, value) {
          if (typeof nameOrObject === 'string') {
            bindingHandlersObject[nameOrObject] = value;
          } else if (typeof nameOrObject === 'object') {
            if (value !== undefined) {
              options.onError(
                new Error("Given extraneous `value` parameter (first param should be a string, but it was an object)." + nameOrObject));
            }
            extend(bindingHandlersObject, nameOrObject);
          } else {
            options.onError(
              new Error("Given a bad binding handler type: " + nameOrObject));
          }
        }
      },
      'get': {
        configurable: true,
        value: function getBindingHandler(name) {
          // NOTE: Strict binding checking ought to occur here.
          return bindingHandlersObject[name];
        }
      }
    });
  }
docs: Add non-enumerable `get` and `set` properties.
   bindingHandlers.set(nameOrObject, value) --- Examples:  bindingHandlers.set('name', bindingDefinition) bindingHandlers.set({ text: textBinding, input: inputBinding })