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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 run(self):
 """Start the FTP Server for pulsar search."""

        self._log.info('Starting Pulsar Search Interface')
        # Instantiate a dummy authorizer for managing 'virtual' users
        authorizer = DummyAuthorizer()

        # Define a new user having full r/w permissions and a read-only
        # anonymous user
        authorizer.add_user(self._config['login']['user'],
                            self._config['login']['psswd'], '.',
                            perm=self._config['login']['perm'])
        authorizer.add_anonymous(os.getcwd())

        # Instantiate FTP handler class
        handler = FTPHandler
        handler.authorizer = authorizer
        handler.abstracted_fs = PulsarFileSystem

        # Define a customized banner (string returned when client connects)
        handler.banner = "SKA SDP pulsar search interface."

        # Instantiate FTP server class and listen on 0.0.0.0:7878
        address = (self._config['address']['listen'],
                   self._config['address']['port'])
        server = FTPServer(address, handler)

        # set a limit for connections
        server.max_cons = 256
        server.max_cons_per_ip = 5

        # start ftp server
        server.serve_forever()