anchor.diff:  both the `timeslot` and `room` fields require an `@PlanningVariable` annotation.
   Their containing class, `Lesson`, requires an `@PlanningEntity` annotation.
   
  -Create the `src/main/java/org/acme/domain/Lesson.java` class:
  +Create the `src/main/java/org/acme/optaplanner/domain/Lesson.java` class:
   
   [source,java]
   ----
  -package org.acme.domain;
  +package org.acme.optaplanner.domain;
   
   import org.optaplanner.core.api.domain.entity.PlanningEntity;
   import org.optaplanner.core.api.domain.lookup.PlanningId;
  
positive.code: which runs solvers in a separate thread pool
  and can solve multiple datasets in parallel.
  
  Create the `src/main/java/org/acme/solver/TimeTableResource.java` class:
  
  [source,java]
  ----
  package org.acme.rest;
  
  import java.util.UUID;
  import java.util.concurrent.ExecutionException;
  
negative.code: import javax.inject.Inject;
  
  import io.quarkus.test.junit.QuarkusTest;
  import org.acme.optaplanner.domain.Room;
  import org.acme.optaplanner.domain.Timeslot;
  import org.acme.optaplanner.domain.Lesson;
  import org.acme.optaplanner.domain.TimeTable;
  import org.acme.optaplanner.rest.TimeTableResource;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.Timeout;
  
  