<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_partition(self, partition):
 """Add partition to partition list."""

        assert(partition not in self._partitions)
        # Add partition to existing set
        self._partitions.add(partition)
        # Add broker to replica list
        partition.add_replica(self)