archaius-core/src/main/java/com/netflix/config/ConcurrentCompositeConfiguration.java
public  boolean removeConfiguration(Configuration config)
    {
        // Make sure that you can't remove the inMemoryConfiguration from
        // the CompositeConfiguration object       
        if (!config.equals(containerConfiguration))
        {
            String configName = getNameForConfiguration(config);
            if (configName != null) {
                namedConfigurations.remove(configName);
            }
            return configList.remove(config);
        } else {
            throw new IllegalArgumentException("Can't remove container configuration");
        }
    }
public  boolean removeConfiguration(Configuration config)
    {
        // Make sure that you can't remove the inMemoryConfiguration from
        // the CompositeConfiguration object       
        if (!config.equals(containerConfiguration))
        {
            String configName = getNameForConfiguration(config);
            if (configName != null) {
                namedConfigurations.remove(configName);
            }
            return configList.remove(config);
        } else {
            throw new IllegalArgumentException("Can't remove container configuration");
        }
    }
Remove a configuration. The container configuration cannot be removed.

@param config The configuration to remove