Our agent application creates and manages one MIB, our subset of MIB-II. To do so, it instantiates the corresponding RFC1213_MIB MBean that was generated by the mibgen tool (see 16.1 MIB Development Process). We give it a meaningful object name and then we register it in the MBean server.
The registration process enables the MBean to instantiate and register other MBeans that represent the groups of the MIB and the entries of its tables. The set of all these MBeans at the end of registration makes up the MBean representation of the MIB. If an SNMP manager later adds entries to a table, the MIB implementation registers the new entry MBean into the MBean server as well.
If you do not want to expose a MIB through the MBean server, you do not have to register it. However, you still need to create all of its other MBean objects so that the SNMP adaptor can access all of its groups and table entries. The generated code provides the init method in the main MBean of the MIB. Calling this method creates all necessary MBean objects without registering them in the MBean server.