<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def init_with_brain(self, brain):
 """Initialize with a catalog brain """

        self._uid = api.get_uid(brain)
        self._brain = brain
        self._catalog = self.get_catalog_for(brain)
        self._instance = None