PreferredAppSignature
const char* nodePreferredApp = model->PreferredAppSignature();
__FILE__, __LINE__, model->PreferredAppSignature(),
model->MimeType(), model->PreferredAppSignature());
model->PreferredAppSignature());
const char* PreferredAppSignature() const;
if (model.PreferredAppSignature()[0]) {
if (be_roster->FindApp(model.PreferredAppSignature(), &preferredRef)
queryIterator->PushUniqueSignature(model.PreferredAppSignature());