<PackageReference Include="NUnit" Version="5.0.0" />

NUnit.Framework.Internal.Execution.SimpleWorkItemDispatcher

SimpleWorkItemDispatcher handles execution of WorkItems by directly executing them. It is provided so that a dispatcher is always available in the context, thereby simplifying the code needed to run child tests.
public int LevelOfParallelism { get; }

The level of parallelism supported

public void CancelRun()

Cancel the ongoing run. If no run is in process, the call has no effect.

public void Dispatch(WorkItem work)

Dispatch a single work item for execution by executing it directly.

public void Start(WorkItem topLevelWorkItem)

Start execution, creating the execution thread, setting the top level work and dispatching it.