Example used in testcase
request method = "POSTsss"

I would like to allow GET / POST / DELETE methods only. otherwise send 501 response.
if ($request_method !~* ^(GET|DELETE|POST)$ ) {
return 501 '{ "ver": "1.1.2", "txnid": "", "timestamp": "", "errorCode": "NotImplemented", "errorMsg": "Request Method is not implemented"}';
}