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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 pub_close(self):
        '''
        Disconnect an existing publisher socket and remove it from the local
        thread's cache.
        '''
        if hasattr(self._sock_data, 'sock'):
            self._sock_data.sock.close()
            delattr(self._sock_data, 'sock')