static String[] filterQualifiedProfiles(String[] whole, String moduleName) {
		List<String> result = new ArrayList<String>();
		for (String raw : whole) {
			String prefix = moduleName + HIERARCHICAL_PROFILE_SEPARATOR;
			if (raw.startsWith(prefix)) {
				result.add(raw.substring(prefix.length()));
			}
		}
		return result.toArray(new String[result.size()]);
	}
The composed module itself never needs to activate profiles. It's the submodules that should. The keys
returned here are special constructs that are decoded by {@link PrefixNarrowingModuleOptions}.
spring-xd-module/src/main/java/org/springframework/xd/module/options/HierarchicalCompositeModuleOptionsMetadata.java