public MessageBus get() {
		return BUS;
	}
This class holds the static reference to the message bus (especially local messagebus) and makes it available at
Spark executors in local mode. This makes it possible to use the same message bus object used by the container.

@author Mark Fisher
@since 1.1
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/plugins/spark/streaming/LocalMessageBusHolder.java