<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _elect_dest_replication_group( self, replica_count_source, under_replicated_rgs, partition, ):
 """Decide destination replication-group based on replica-count."""

        min_replicated_rg = min(
            under_replicated_rgs,
            key=lambda rg: rg.count_replica(partition),
        )
        # Locate under-replicated replication-group with lesser
        # replica count than source replication-group
        if min_replicated_rg.count_replica(partition) < replica_count_source - 1:
            return min_replicated_rg
        return None