public SipTransactionContext sendSipMessage(SipMessage message,SipTransactionContext.INotifySipProvisionalResponse callback) throws NetworkException, PayloadException {
  return mSipInterface.sendSipMessageAndWait(message,callback);
}

public SipTransactionContext sendSipMessage ( SipMessage message , SipTransactionContext . INotifySipProvisionalResponse callback ) throws NetworkException , PayloadException { return mSipInterface . sendSipMessageAndWait ( message , callback ) ; }
send a sip message and create a context to wait a response
