can not update comment while updating the issue state

[Nikhil Shiragave]

{
"update": {
"comment": [
{
"add": {
"body": "{{comment}}"
}
}
]
},

"resolution": {
"name": "{{resolution}}"
}
,
"transition": {
"id": "{{transition_id}}"
}
}

getting result as 

{"errorMessages":[],"errors":{"comment":"Comment body can not be empty!"}}
<Response [400]>