private void clearPropertySources() {
		List<String> names = new ArrayList<String>();
		for (PropertySource<?> ps : getPropertySources()) {
			names.add(ps.getName());
		}
		for (String name : names) {
			getPropertySources().remove(name);
		}

		Map<String, Object> empty = Collections.emptyMap();
		getPropertySources().addLast(new MapPropertySource(SYSTEM_PROPERTIES_PROPERTY_SOURCE_NAME, empty));
		getPropertySources().addLast(new MapPropertySource(SYSTEM_ENVIRONMENT_PROPERTY_SOURCE_NAME, empty));

	}
Remove all property sources carried over from the parent environment. Add some empty sources where Spring boot
expects them.
spring-xd-module/src/main/java/org/springframework/xd/module/core/ModuleEnvironment.java