How to create a SOAP request in EWS? - soap

Question

I've got such kind of class with required login, password, url and domain:
class Service
{
public ExchangeService service;
public void Connect()
{
const string exchangeUser = "login";
const string exchangePassword = "password";
const string exchangeUri = "url";
service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
service.UseDefaultCredentials = true;
service.Credentials = new WebCredentials(exchangeUser, exchangePassword, "domain");
service.Url = new Uri(exchangeUri);
}
}
And I need to add such method as CreateAppointment()
public void CreateAppointment()
{
Appointment appointment = new Appointment(service);
appointment.Subject = "Team building exercise";
appointment.Body = "Let's learn to really work as a team and then have lunch!";
appointment.Start = DateTime.Now.AddHours(2);
appointment.End = appointment.Start.AddHours(4);
appointment.Location = "Some city";
appointment.RequiredAttendees.Add("somebody#something.com");
appointment.ReminderMinutesBeforeStart = 30;
appointment.Save(SendInvitationsMode.SendToNone);
}
Save() method doesn't work because of some reasons for creating service and appointment objects. So I need to rewrite this method using xml request. And I've got an example of SOAP request from msdn https://msdn.microsoft.com/en-us/library/office/dd633661(v=exchg.80).aspx
How could I insert the SOAP request instead of CreateAppointment() method? I've got no idea what to do with xml code to make it work as CreateAppointment() method.