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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 unregister_header(self, name):
 """ Unregister support for the SHIM header with the given `name`. If the header is currently not registered as supported, :class:`KeyError` is raised. """


        self._node.unregister_feature(
            "#".join([namespaces.xep0131_shim, name])
        )