Notifications mark viewed

**Brief description:**

- Mark a notification as viewed.

**Endpoint：**

- `https://www.mywebsite.com/api/v1.0/notifications_mark_viewed`
  
**Method:**

- POST / GET

**Parameter:**

|Parameter name|Required|Type|Explain|
|:----    |:---|:----- |-----   |
|api_key_token |Yes  |string |Your API key   |
|notification_guid| Yes|integer| A notification  `GUID`|
**Example Response **

``` 
{
{
    "merchant": "Open Source Social Network",
    "url": "http:\/\/www.mywebsite.com\/",
    "time_token": 1569332608,
    "payload": {
        "notification": {
            "guid": "4",
            "type": "like:post",
            "poster_guid": "27",
            "owner_guid": "1",
            "subject_guid": "110",
            "viewed": "",
            "time_created": "1569331959",
            "item_guid": "110"
        },
        "poster": {
            "guid": "27",
            "fullname": "Meagan McLaughlin",
            "icon": "http:\/\/www.mywebsite.com\/avatar\/zKutch\/small\/8715c874616ebf0391af044f974b554e.jpeg"
        },
        "entity": false,
        "post": false
    },
    "code": "100",
    "message": "Request successfully executed"
}
```

**Return payload parameter description **

|Parameter name|Explain|
|:-----  |-----|
|entity| if it is releated to any entity other than profile and cover photo update|
|group| if it is releated to the group member requests, it will contain group details|
|post| If it is releated to post, this will contain a wall post details|

** Remakrs **
- If it is failed you will get error code `200`