/// <summary>
/// Create a new <Sip/> element and append it as a child of this element.
/// </summary>
/// <param name="sipUrl"> SIP URL, the body of the TwiML Element. </param>
public Refer ReferSip(Uri sipUrl = null)
{
var newChild = new ReferSip(sipUrl);
this.Append(newChild);
return(this);
}
public Refer ReferSip(ReferSip referSip)
{
this.Append(referSip);
return(this);
}