private String toString(List<String> elements) {
		StringBuilder s = new StringBuilder();
		for (int i = 0; i < elements.size(); i++) {
			if (i > 0) {
				s.append('.');
			}
			s.append(elements.get(i));
		}
		return s.toString();
	}
@author Andy Clement
@author David Turanski
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/stream/dsl/ChannelNode.java