# CachedMessageBlock.GetOldestSequenceToken(ICacheDataAdapter)

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.cachedmessageblock/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.cachedmessageblock/methods/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Common/PooledCache/CachedMessageBlock.cs#L163)

```csharp
public StreamSequenceToken GetOldestSequenceToken(ICacheDataAdapter dataAdapter)
```

Gets the sequence token of the oldest message in this block

### Parameters

- `dataAdapter` (`ICacheDataAdapter`): The data adapter.

### Returns

The sequence token of the oldest message in this block.