# NameValueCollectionSurrogate.HasNullKey

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.serialization/orleans.serialization.codecs.namevaluecollectionsurrogate/) | [Fields](/orleans/docs/api/csharp/microsoft.orleans.serialization/orleans.serialization.codecs.namevaluecollectionsurrogate/fields/)

```csharp
[Orleans.Id(1)]
public bool HasNullKey
```

Gets or sets a value indicating whether the collection contains a null key.