nsISOAPTransport Interface

 Add listener for unsolicited messages arriving on the transport.  Listeners
  are provided with the opportunity to accept and process messages.  Typically
  a listener will be a service dispatcher.  Listeners will be invoked in the
  reverse order of declaration, allowing more local service dispatchers to
  temporarily override permanent service dispatchers.  This will fail if the
  desired listener was already added to the transport with the specified
  capture flag or if the transport does not support incoming messages.

 @param aListener The listener to recieve unsolicited messages from the
   transport.

 @param aCapture True if the listener should capture the message before
   later-declared services.

void addListener(in nsISOAPTransportListener aListener, in boolean aCapture)

 Send the specified message to the specified destination synchronously waiting 
 for completion and any response.
 This will fail if there is any failure in the setup of the message exchange.
 Later errors will only be known through the response listener.  Failures of the
 call itself will be contained in the response passed to the response listener.

 @param aCall Actual message to be sent.

 @param aListener Handler to be invoked (single threaded) as each response is 
  received and finally with null.  If specified as null, no responses are returned.

 @param response Message to recieve response and be handled by listener.  May be 
   null if listener is null.

nsISOAPCallCompletion asyncCall(in nsISOAPCall aCall, in nsISOAPResponseListener aListener, in nsISOAPResponse aResponse)

 Remove listener for unsolicited messages arriving on the transport.  This
  will fail if the specified listener was not added with the specified
  capture setting.

 @param aListener The listener to stop from recieving unsolicited messages 
  from the transport.

 @param aCapture True if the listener was added to capture the message before
   later-declared services (must be specified to remove, since a listener
   may be registered as both).

void removeListener(in nsISOAPTransportListener aListener, in boolean aCapture)

 Send the specified message to the specified destination.
 This will fail if synchronous calls are not supported or if there is any
 failure in the actual message exchange.  Failure of the call itself will be
 contained in the response.

 @param aCall Actual message to be sent.

 @param aResponse Message to be recieved.  Calling synchronously assumes that 
   exactly one response is expected.

void syncCall(in nsISOAPCall aCall, in nsISOAPResponse aResponse)