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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def register_cmdfinalization_hook(self, func: Callable[[plugin.CommandFinalizationData], plugin.CommandFinalizationData]) -> None: """Register a hook to be called after a command is completed, whether it completes successfully or not."""

        self._validate_cmdfinalization_callable(func)
        self._cmdfinalization_hooks.append(func)