实例化一个带有object类型的字典时，会报错。

首先，从文档中可以注意到，是可以用字典这种类型的。

QQ图片20201018144001.png721x611 61.2 KB

然后我遇到了问题，这里写了个简单的例子来描述一下：

public class MainClass
{
    public void Main()
    {
        AVObject.RegisterSubclass<Test>();
        Test a = new Test()
        {
            A = new Dictionary<object, string>()      //这一句会报错,但是上述文档中显示可以如此，报错情况如下：
           // A = new Dictionary<string,string>()    但是如果改为string或者int这种  就不会有任何问题
        };
        a.A.Add(123,"456");
        a.SaveAsync();
    }
}

[AVClassName("Test")]
public class Test:AVObject
{
    [AVFieldName("a")]
    public Dictionary<object, string> A
    {
        get => GetProperty<Dictionary<object, string>>("A");
        set => SetProperty(value, "A");
    }
}

报错：MissingMethodException: Constructor on type 'LeanCloud.Storage.Internal.FlexibleDictionaryWrapper`2[[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' not found.
System.RuntimeType.CreateInstanceImpl (System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes, System.Threading.StackCrawlMark& stackMark) (at :0)

这... 好吧，谢谢