Problem with tests

I would like to give some feedback about ...

I can't understand what is wrong!

Island: Incinerator Mission: The Defenders

When I click on button "run" all asserts run correctly. But when I click on button "check" the error appears. There is information about the error: unit1 = Defender() unit2 = Rookie() fight(unit1, unit2) unit_1.health

As I understood my code cannot handle a class like Rookie. What is this type and where did it come from? There was no such type in the conditions of mission. There were only Warrior, Knight and Defender So I need your help. Thanks.

From: alrus