/**
  * Removes a classroom from the teacher
  *
  * @param hour The hour of the classroom to remove
  * @return Whether or not the hour existed beforehand
  */
 public boolean removeClassroom(int hour) {
   for (Classroom classroom : classrooms) {
     if (classroom.getHour() == hour) {
       return classrooms.remove(classroom);
     }
   }
   return false;
 }
  /**
   * Gets a classroom the teacher has
   *
   * @param hour The hour of the classroom to get
   * @return The requested classroom
   * @throws java.lang.IllegalArgumentException If teacher doesn't have a class during hour
   */
  public Classroom getClassroom(int hour) {
    for (Classroom classroom : classrooms) {
      if (classroom.getHour() == hour) {
        return classroom;
      }
    }

    throw new IllegalArgumentException();
  }