Registry for modeler MBeans. This is the main entry point into modeler. It provides methods to create and manipulate model mbeans and simplify their use. Starting with version 1.1, this is no longer a singleton and the static methods are strongly deprecated. In a container environment we can expect different applications to use different registries. This class is itself an mbean. IMPORTANT: public methods not marked with @since x.x are experimental or internal. Should not be used.