Question “DefaultTrackableEventHandler” C# script

Hi there,

I am following a tutorial to create an AR feature and got to the last step and got confused. The tutorial states:
"Go to the search bar within your project Hierarchy panel and search for “DefaultTrackableEventHandler” C# script. Double-click to open in Unity’s Monodevelop. To create a public game object to store the “Finder” game object you just created, navigate to the section of the script labelled “#region PRIVATE_MEMBER_VARIABLES” (or “#region PROTECTED_MEMBER_VARIABLES”) and add the following script within this region. Save your changes"

However, when I tried to do it in Unity, I get this: "No results found."

Thoughts on the situation?

Thanks

 

Thanks