archaius-core/src/main/java/com/netflix/config/ConfigurationManager.java
public static AbstractConfiguration getConfigInstance() {
        if (instance == null) {
            synchronized (ConfigurationManager.class) {
                if (instance == null) {
                    instance = getConfigInstance(Boolean.getBoolean(DynamicPropertyFactory.DISABLE_DEFAULT_CONFIG));
                }
            }
        }
        return instance;
    }
public static AbstractConfiguration getConfigInstance() {
        if (instance == null) {
            synchronized (ConfigurationManager.class) {
                if (instance == null) {
                    instance = getConfigInstance(Boolean.getBoolean(DynamicPropertyFactory.DISABLE_DEFAULT_CONFIG));
                }
            }
        }
        return instance;
    }
Get the current system wide configuration. If there has not been set, it will return a default
{@link ConcurrentCompositeConfiguration} which contains a SystemConfiguration from Apache Commons
Configuration and a {@link DynamicURLConfiguration}.