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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_extensions(self, namespace):
 """Register any extensions under the given namespace."""


        # Register any extension classes for this class.
        extmanager = ExtensionManager(
            'extensions.classes.{}'.format(namespace),
            propagate_map_exceptions=True
        )

        if extmanager.extensions:
            extmanager.map(util.register_extension_class, base=self)

        # Register any extension methods for this class.
        extmanager = ExtensionManager(
            'extensions.methods.{}'.format(namespace),
            propagate_map_exceptions=True
        )
        if extmanager.extensions:
            extmanager.map(util.register_extension_method, base=self)