private static void CreateClosuresForTestNodes(NtwkDBContext context, TestIDsSet idSet)
 {
     int?[] ancestors = new int?[]
     {
         null, idSet.NodesIDs[0],                    //Node1
         null, idSet.NodesIDs[0], idSet.NodesIDs[1], //Node2
         null, idSet.NodesIDs[2],                    //Node3
     };
     int[] descIndex = new int[]
     {
         0, 0, 1, 1, 1, 2, 2
     };
     int[] distance = new int[]
     {
         0, 0, 1, 1, 0, 0, 0
     };
     context.AddRange(Enumerable.Range(0, 7)
                      .Select(i => new NodeClosure
     {
         ID           = 0,
         AncestorID   = ancestors[i],
         DescendantID = idSet.NodesIDs[descIndex[i]],
         Distance     = distance[i]
     })
                      );
     context.SaveChanges();
 }