text: 
  
  class Timeslot():
      """
      A timeslot a lecture can be held at.
      """
      def __init__(self, day, start, end):
          
          self._day = day
          self._start = start
          self._end = end
          
      def __repr__(self):
          return '<Timeslot {} {}-{}>'.format(
              self._day, self._start, self._end)
      
      def __str__(self):
          return '{} {}-{}'.format(
              self._day, self._start, self._end)
          
      def __hash__(self):
          return hash(self._day + self._start + self._end)
      
      def __eq__(self, other):
          return (self._day == other._day and
                  self._start == other._start and
                  self._end == other._end)