# IStreamNamespacePredicate.IsMatch(string)

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

```csharp
public abstract bool IsMatch(string streamNamespace)
```

Defines if the consumer grain should subscribe to the specified namespace.

### Parameters

- `streamNamespace` (`string`): The target stream namespace to check.

### Returns

`true`, if the grain should subscribe to the specified namespace; `false`, otherwise.