public Object getMutex(@Nonnull final DomainPair domainPair) {
        return interner.intern(domainPair);
    }
Generates an object that is suitable as a mutex for operations that involve the provided DomainPair instance.

@param domainPair The DomainPair for which the mutex is issued
@return An object suitable to be a mutex.
xmppserver/src/main/java/org/jivesoftware/openfire/server/OutgoingSessionPromise.java