[iControl Rest API]How to create the device group with devices using iControl Rest

Hi,

I have created device group and tried to add device using the below URL and json, throwing the error as name is missing. Am I missing something here and can anyone help me here?

https:///mgmt/tm/cm/device-group/~Common~Demo_Device_Group/devices

{"kind":"tm:cm:device-group:devices:devicescollectionstate","selfLink":"","items":[{"kind":"tm:cm:device-group:devices:devicesstate","name":"B2150-B1.cisco.com","partition":"Common","fullPath":"/Common/B2150-B1.cisco.com","generation":1,"selfLink":""}]}

Regards, Prakash.K