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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 connection(self):
 """Request-bound database connection."""

        assert flask.has_request_context(), \
               'tried to connect zodb outside request'
        if not self.is_connected:
            connector = flask.current_app.extensions['zodb']
            flask._request_ctx_stack.top.zodb_connection = connector.db.open()
            transaction.begin()
        return flask._request_ctx_stack.top.zodb_connection