Mark as Read Forum REST Endpoint error

When i tried the API "Mark as Read Forum" Endpoint error was thrown below:

Example: 

method : POST

url : http//myhome/api.ashx/v2/forums/2/read.json

request headers:

Authorization : OAuth token

Rest-Method : PUT

Request Body:

{
"HasRead" : "True"
}

Response:

{
"": null,
"Errors": [
"HasRead is required"
]
}