This interface allows a client to get some shell's info. Warning! The protocol described in this file is currently in the testing phase. Backward compatible changes may be added together with the corresponding interface version bump. Backward incompatible changes can only be done by creating a new major version of the extension. The format of the shortcut key is 'Modify+Key', such as 'Ctrl+Alt+T'. If the format is wrong, the synthesizer will give a "format error". If the shortcut key is already registered, the compositor will give a "register error" and issue a destruction to the context. This interface allows a client to listen a shortcut action. Warning! The protocol described in this file is currently in the testing phase. Backward compatible changes may be added together with the corresponding interface version bump. Backward incompatible changes can only be done by creating a new major version of the extension. Destroy the context object.