Why does my IEnumerator<AppiumWebElement> not have .Where()?

Question

The title mostly explains my question, my IEnumerable<AppiumWebElement> does not have a .Where method, and I'm hoping to learn why.

I have a method that returns an IEnumerable<AppiumWebElement>, as follows:

public IEnumerable<AppiumWebElement> GetLayers()
{
  var items = PaneOrView.FindElementsByClassName("TreeViewItem");
  List<AppiumWebElement> layers = new List<AppiumWebElement>();
  foreach(AppiumWebElement item in items)
  {
    string automationId = item.AutomationId(); 
    if (automationId != null && automationId.Contains("Layer"))
    {
      layers.Add(item);
    }
  }
  return layers.AsEnumerable();
}

When I check whether .Where is present on the return item in this method (using code completion), I get a full list of methods I would expect to see from an IEnumerable.

However, when I later use this method from another namespace, for example like this:

var test = Contents.GetLayers();

The result in test doesn't contain .Where or any of the other methods I would expect to see from an IEnumerable. Any idea why?

Thanks for any pointers!

Answer 1

Where() and other methods in Linq are extension methods that you are using. You need to import System.Linq:

using System.Linq;