int total = result.paginationOutput.totalPages;
     for (int i = 2; i < total + 1; i++)
         {
     
          await Task.Factory.StartNew(() =>
          {
             result = client.findItemsByProduct(i);
          });
          newList.AddRange(result.searchResult.item);
     
          }
         }
     return newList;
           
    forEach item {
      result = item.makeWebRequest();
    }
    foreach item {
      List.addRange(item.harvestResults);
    }
           
    var results = new ConcurrentBag<ItemType>(result.pagination.totalPages);
    using (var e = new CountdownEvent(result.pagination.totalPages))
    {
        for (int i = 2; i <= result.pagination.totalPages+1; i++)
        {
            Task.Factory.StartNew(() => return client.findItemsByProduct(i))
                        .ContinueWith(items => {
                            results.AddRange(items);
                            e.Signal(); // signal task is done
                        });
        }
        // Wait for all requests to complete
        e.Wait();
    }
    // Process results
    foreach (var item in results)
    {
        ...
    }
           
    public static Task<Item[]> Foo()
    {
        int total = result.paginationOutput.totalPages;
     
        var tasks = new List<Task<Item>>();
     
        for (int i = 2; i < total + 1; i++)
        {
            tasks.Add(Task.Factory.StartNew(() => client.findItemsByProduct(i)));
        }
     
        return Task.WhenAll(tasks);
    }
           
    int total = result.paginationOutput.totalPages;
     
    // Start all downloads; each download is represented by a task.
    Task<Item[]>[] tasks = Enumerable.Range(2, total - 1)
        .Select(i => client.findItemsByProductAsync(i)).ToArray();
     
    // Wait for all downloads to complete.
    Item[][] results = await Task.WhenAll(tasks);
     
    // Flatten the results into a single collection.
    return results.SelectMany(x => x).ToArray();