<PackageReference Include="System.Diagnostics.DiagnosticSource" Version="10.0.0-preview.2.25163.2" />

SampleActivity<T>

public sealed delegate SampleActivity<T> : MulticastDelegate
A delegate that defines the signature of the ActivityListener callbacks used in the sampling process.
public SampleActivity(object object, IntPtr method)

public virtual IAsyncResult BeginInvoke(ref ActivityCreationOptions options, AsyncCallback callback, object object)