public synchronized final T lookupOrCreateSharedChannel(String name) {
			T channel = lookupSharedChannel(name);
			if (channel == null) {
				channel = createAndRegisterChannel(name);
			}
			return channel;
		}
Looks up or optionally creates a new channel to use.
@author Eric Bottard
spring-xd-messagebus-spi/src/main/java/org/springframework/xd/dirt/integration/bus/MessageBusSupport.java