public override object Execute(IGraphProcessingEnvironment procEnv)
 {
     object[] values = new object[ArgExprs.Count - 1];
     for(int i = 1; i < ArgExprs.Count; ++i)
     {
         values[i - 1] = ArgExprs[i].Evaluate(procEnv);
     }
     procEnv.DebugExiting((string)ArgExprs[0].Evaluate(procEnv), values);
     return null;
 }