anchor.diff:  * If it adheres to all hard constraints, then it is a _feasible_ solution,
   for example, a solution with the score `0hard/-7soft`.
   
  -Create the `src/main/java/org/acme/domain/TimeTable.java` class:
  +Create the `src/main/java/org/acme/optaplanner/domain/TimeTable.java` class:
   
   [source,java]
   ----
  -package org.acme.domain;
  +package org.acme.optaplanner.domain;
   
   import java.util.List;
   
  
positive.code: For simplicity's sake, all rooms are without capacity limits
  and they can accommodate all lessons.
  
  Create the `src/main/java/org/acme/domain/Room.java` class:
  
  [source,java]
  ----
  package org.acme.domain;
  
  public class Room {
  
  
negative.code: 
      @Override
      public String toString() {
          return dayOfWeek + " " + startTime;
      }
  
  }
  