@Override
		public int compareTo(Id that) {
			int c = this.containerId.compareTo(that.containerId);
			if (c == 0) {
				c = this.unitName.compareTo(that.unitName);
			}
			if (c == 0) {
				c = this.moduleType.compareTo(that.moduleType);
			}
			if (c == 0) {
				c = this.moduleLabel.compareTo(that.moduleLabel);
			}
			if (c == 0) {
				int x = this.index;
				int y = that.index;
				c = (x < y) ? -1 : ((x == y) ? 0 : 1);
			}
			return c;
		}
Return the "fully qualified" id string for the module instance
this metadata object is tracking. The format for this string is
"deploymentUnitName.type.label.index", for example "ticktock.sink.log.1".

@return fully qualified id string
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/module/store/ModuleMetadata.java