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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 _playbook_arguments(self):
 """Argument specific to playbook apps. These arguments will be passed to every playbook app by default. --tc_playbook_db_type type The DB type (currently on Redis is supported). --tc_playbook_db_context context The playbook context provided by TC. --tc_playbook_db_path path The DB path or server name. --tc_playbook_db_port port The DB port when required. --tc_playbook_out_variables vars The output variable requested by downstream apps. """


        self.add_argument(
            '--tc_playbook_db_type', default=self._tc_playbook_db_type, help='Playbook DB type'
        )
        self.add_argument(
            '--tc_playbook_db_context',
            default=self._tc_playbook_db_context,
            help='Playbook DB Context',
        )
        self.add_argument(
            '--tc_playbook_db_path', default=self._tc_playbook_db_path, help='Playbook DB path'
        )
        self.add_argument(
            '--tc_playbook_db_port', default=self._tc_playbook_db_port, help='Playbook DB port'
        )
        self.add_argument(
            '--tc_playbook_out_variables', help='Playbook output variables', required=False
        )