@NotBlank
	public String getUsername() {
		return username;
	}
Factors out options for the typical connection setup to RabbitMQ.

@author Eric Bottard
@author Gary Russell
@author Glenn Renfro
@author Gary Russell
@author David Turanski
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/modules/metadata/RabbitConnectionMixin.java