public virtual void Execute(PvmExecutionImpl execution)
{
// Invariant: execution is the Scope Execution for the activity's flow scope.
var activityToStart = execution.NextActivity;
execution.NextActivity = null;
var propagatingExecution = execution.CreateConcurrentExecution();
// set next activity on propagating execution
propagatingExecution.Activity = (activityToStart);
ConcurrentExecutionCreated((PvmExecutionImpl)propagatingExecution);
}