private async Task<Call> HangupCallAsyncInternal(string callSid, HangupStyle style)
{
Require.Argument("CallSid", callSid);
var request = new RestRequest();
request.Method = Method.POST;
request.Resource = "Accounts/{AccountSid}/Calls/{CallSid}.json";
request.AddUrlSegment("CallSid", callSid);
request.AddParameter("Status", style.ToString().ToLower());
var result = await ExecuteAsync(request, typeof(Call));
return (Call)result;
}