In this framework, all the objects being monitored will:
1 Provide interface and default implementation of CallBack.
2 The default implementation is a class assigned by external configuration file. This class can be defined by customers. The configuration file will not be merged into btt.xml or other files, but at the runtime, be loaded into ClassPath\moniter.xml.
3 To determine whether to use CallBack, Before, after and around of Aspect can be assigned true/false. For example,
Note UDTT provides the default implementation. You should make sure this class is implemented.
