old_contents: import pulp
  from conference_scheduler.resources import (
      Person, Room, Slot, Session, EventType, Event, Role, Demand,
      Unavailability, CHAIR
  )
  from conference_scheduler import scheduler
  
  people = {
      'alice': Person(name='Alice', max_chair_sessions=3),
      'bob': Person(name='Bob', max_chair_sessions=3),
      'charlie': Person(name='Charlie')
  }
  
  event_types = {
      'workshop': EventType(name='workshop'),
      'talk': EventType(name='talk')
  }
  
  rooms = {
      'main_hall': Room(
          name='Main Hall', capacity=500, suitability=event_types['talk']),
      'room_1': Room(
          name='Room 1', capacity=50, suitability=event_types['workshop'])
  }
  
  slots = (
      Slot(starts_at='15-Sep-2016 09:30', ends_at='15-Sep-2016 10:00'),
      Slot(starts_at='15-Sep-2016 10:00', ends_at='15-Sep-2016 10:30'),
      Slot(starts_at='15-Sep-2016 11:30', ends_at='15-Sep-2016 12:00'),
      Slot(starts_at='15-Sep-2016 12:00', ends_at='15-Sep-2016 12:30'),
  )
  
  sessions = (
      Session(slots=(slots[0], slots[1])),
      Session(slots=(slots[2], slots[3]))
  )
  
  roles = {
      'speaker': Role(name='speaker'),
      'leader': Role(name='leader'),
      'mentor': Role(name='mentor')
  }
  
  events = {
      'talk_1': Event(
          name='Talk 1',
          event_type=event_types['talk'],
          roles={roles['speaker']: people['alice']}
      ),
      'talk_2': Event(
          name='Talk 2',
          event_type=event_types['talk'],
          roles={roles['speaker']: people['bob']}
      ),
      'workshop_1': Event(
          name='Workshop 1',
          event_type=event_types['workshop'],
          roles={roles['leader']: people['charlie']}
      )
  }
  
  demand = (
      Demand(event=events['talk_1'], audience=300),
      Demand(event=events['talk_2'], audience=300),
      Demand(event=events['workshop_1'], audience=30),
  )
  
  unavailability = (
      Unavailability(person=people['alice'], slot=slots[0]),
      Unavailability(person=people['alice'], slot=slots[1]),
      Unavailability(person=people['bob'], slot=slots[2]),
      Unavailability(person=people['bob'], slot=slots[3]),
  )
  
  
  def test_is_valid_schedule():
      # Test empty schedule
      schedule = tuple()
      problem = pulp.LpProblem()
      assert not scheduler.is_valid_schedule(schedule, problem)
  
  
  def test_schedule():
      pass
  
new_contents: import pulp
  from conference_scheduler.resources import (
      Person, Room, Slot, Session, EventType, Event, Role, Demand,
      Unavailability
  )
  from conference_scheduler import scheduler
  
  people = {
      'alice': Person(name='Alice', max_chair_sessions=3),
      'bob': Person(name='Bob', max_chair_sessions=3),
      'charlie': Person(name='Charlie')
  }
  
  event_types = {
      'workshop': EventType(name='workshop'),
      'talk': EventType(name='talk')
  }
  
  rooms = {
      'main_hall': Room(
          name='Main Hall', capacity=500, suitability=event_types['talk']),
      'room_1': Room(
          name='Room 1', capacity=50, suitability=event_types['workshop'])
  }
  
  slots = (
      Slot(starts_at='15-Sep-2016 09:30', ends_at='15-Sep-2016 10:00'),
      Slot(starts_at='15-Sep-2016 10:00', ends_at='15-Sep-2016 10:30'),
      Slot(starts_at='15-Sep-2016 11:30', ends_at='15-Sep-2016 12:00'),
      Slot(starts_at='15-Sep-2016 12:00', ends_at='15-Sep-2016 12:30'),
  )
  
  sessions = (
      Session(slots=(slots[0], slots[1])),
      Session(slots=(slots[2], slots[3]))
  )
  
  roles = {
      'speaker': Role(name='speaker'),
      'leader': Role(name='leader'),
      'mentor': Role(name='mentor')
  }
  
  events = {
      'talk_1': Event(
          name='Talk 1',
          event_type=event_types['talk'],
          roles={roles['speaker']: people['alice']}
      ),
      'talk_2': Event(
          name='Talk 2',
          event_type=event_types['talk'],
          roles={roles['speaker']: people['bob']}
      ),
      'workshop_1': Event(
          name='Workshop 1',
          event_type=event_types['workshop'],
          roles={roles['leader']: people['charlie']}
      )
  }
  
  demand = (
      Demand(event=events['talk_1'], audience=300),
      Demand(event=events['talk_2'], audience=300),
      Demand(event=events['workshop_1'], audience=30),
  )
  
  unavailability = (
      Unavailability(person=people['alice'], slot=slots[0]),
      Unavailability(person=people['alice'], slot=slots[1]),
      Unavailability(person=people['bob'], slot=slots[2]),
      Unavailability(person=people['bob'], slot=slots[3]),
  )
  
  
  def test_is_valid_schedule():
      # Test empty schedule
      schedule = tuple()
      problem = pulp.LpProblem()
      assert not scheduler.is_valid_schedule(schedule, problem)
  
  
  def test_schedule():
      pass
  
subject: Remove redundant import