# CopierTester<TValue, TCopier>.IsImmutable

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.serialization.testkit/orleans.serialization.testkit.copiertester-2/) | [Properties](/orleans/docs/api/csharp/microsoft.orleans.serialization.testkit/orleans.serialization.testkit.copiertester-2/properties/)

[Source](https://github.com/dotnet/orleans/blob/b7a9e3e1c9c54b3cec3a467c5734bf7744541bcf/src/Orleans.Serialization.TestKit/CopierTester.cs#L65)

```csharp
protected virtual bool CopierTester<TValue, IsImmutable
```

Gets a value indicating whether the type copied by this codec is immutable.