Provide an easy way for users to add beans (e.g., Gemfire cache configuration) or modify default XD configuration such as serializers, and message converters. A simple approach is to add a well known resource selector such as classpath*:META-INF/spring/xd/extensions or include this path in an extensible @Configuration base class. In addition, we should adopt conventional names for beans that are meant to be extended, e.g. use an xd. prefix.