@Override
      public Future<String> convert(RestRequest restRequest, String input, Callback<String> callback) {
        return convert(restRequest, input, null, callback);
      }
Method to easily create a PUT {@link RestRequest}. This will set {@link RestUtils.InternalKeys#REQUEST_PATH} to a
valid {@link RequestPath} object.
@param headers any associated headers as a {@link JSONObject}.
@param path the path for the request.
@param requestBody the body of the request.
@return A {@link RestRequest} object that defines the request required by the input.
ambry-frontend/src/test/java/com/github/ambry/frontend/NamedBlobPutHandlerTest.java