```csharp
using Qdrant.Client;
using Qdrant.Client.Grpc;

var client = new QdrantClient("localhost", 6334);

await client.UpdateCollectionAsync(
	collectionName: "{collection_name}",
	optimizersConfig: new OptimizersConfigDiff { IndexingThreshold = 10000 },
	metadata: new()
	{
		["my-metadata-field"] = new Dictionary<string, Value>
		{
			["key-a"] = "value-a",
			["key-b"] = 42
		},
	}
);
```