This sample shows the Call Hierarchy in action based on a simple food pyramid model defined using simple subject ~ verb ~ object syntax.
Start the extension in the debugger and it automatically opens a file that is ready for the right-click > Peek Call Hierarchy. Otherwise, it can be testing by creating a file with extension .txt and pasting following text:
Coyote eats deer.
Deer eats plants.
Coyote eats lizard.
Lizard eats bird.
Lizard eats frog.
Lizard eats butterfly.
Bird eats seeds.
Frog eats insects.
Butterfly eats fruit.
Right click on a noun or a verb and select Peek Call Hierarchy.
Run the Run Extension Tests configuration and verify in the Debug Console that all tests are passing.