Because the ConfigProxyFactory evaluates the default value eagerly, an NPE is thrown for
Map properties when a null value is passed into Collections.unmodifiableMap, even if the
configuration is actually present and therefore the default is not needed.
Because the ConfigProxyFactory evaluates the default value eagerly, an NPE is thrown for Map properties when a null value is passed into Collections.unmodifiableMap, even if the configuration is actually present and therefore the default is not needed.