async Task AddLeaseAsync()

in src/DurableTask.AzureStorage/Partitioning/LeaseCollectionBalancer.cs [602:673]
64 lines of code
6 McCabe index (conditional complexity)

        async Task AddLeaseAsync(T lease)
        {
            if (this.currentlyOwnedShards.TryAdd(lease.PartitionId, lease))
            {
                bool failedToInitialize = false;
                try
                {
                    await this.leaseObserverManager.NotifyShardAcquiredAsync(lease);
                }
                catch (Exception ex)
                {
                    failedToInitialize = true;

                    // Eat any exceptions during notification of observers
                    this.settings.Logger.PartitionManagerError(
                        this.accountName,
                        this.taskHub,
                        this.workerName,
                        lease.PartitionId,
                        $"Failed to notify observers of {this.leaseType} lease acquisition: {ex}");
                }

                // We need to release the lease if we fail to initialize the processor, so some other node can pick up the parition
                if (failedToInitialize)
                {
                    await this.RemoveLeaseAsync(lease, true);
                }
            }
            else
            {
                // We already acquired lease for this partition but it looks like we previously owned this partition 
                // and haven't completed the shutdown process for it yet.  Release lease for possible others hosts to 
                // pick it up.
                try
                {
                    this.settings.Logger.PartitionManagerWarning(
                        this.accountName,
                        this.taskHub,
                        this.workerName,
                        lease.PartitionId,
                        $"Unable to add {this.leaseType} lease with PartitionId '{lease.PartitionId}' with lease token '{lease.Token}' to currently owned leases.");

                    await this.RemoveLeaseAsync(lease, true);
                    this.settings.Logger.LeaseRemoved(
                        this.accountName,
                        this.taskHub,
                        this.workerName,
                        lease.PartitionId,
                        lease.Token,
                        this.leaseType);
                }
                catch (LeaseLostException)
                {
                    this.settings.Logger.LeaseRemovalFailed(
                        this.accountName,
                        this.taskHub,
                        this.workerName,
                        lease.PartitionId,
                        lease.Token,
                        this.leaseType);
                }
                catch (Exception ex)
                {
                    this.settings.Logger.PartitionManagerError(
                        this.accountName,
                        this.taskHub,
                        this.workerName,
                        lease.PartitionId,
                        $"Encountered a failure when removing a {this.leaseType} lease we previuosly owned: {ex}");
                }
            }
        }