public TcpSource ensureReady() {
		AvailableSocketPorts.ensureReady(this.getClass().getName(), host, port, 2000);
		return this;
	}
Ensure that the TcpSource socket is available by polling it for up to 2 seconds

@return TcpSource to use in fluent API chaining
@throws IllegalStateException if can not connect in 2 seconds.
spring-xd-test-fixtures/src/main/java/org/springframework/xd/test/fixtures/TcpSource.java