public Map<String, String> getCustomAttributes() {
		Map<String, String> customAttributes = new HashMap<String, String>();
		for (String key : this.keySet()) {
			if (!commonAttributeKeys.contains(key)) {
				customAttributes.put(key, this.get(key));
			}
		}
		return customAttributes;
	}
Retrieve the custom attributes for this container. This will not include the values for common keys:
{@value #CONTAINER_ID_KEY}, {@value #PROCESS_ID_KEY}, {@value #HOST_KEY}, {@value #IP_ADDRESS_KEY} and
{@value #GROUPS_KEY}

@return the map of custom attributes
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/cluster/ContainerAttributes.java