code: def slots_overlap(slot, other_slot):
      
      slot_ends_at = ends_at(slot)
      other_ends_at = ends_at(other_slot)
      if (slot.starts_at >= other_slot.starts_at and
          slot_ends_at <= other_ends_at
      ):
          return True
      if (other_slot.starts_at >= slot.starts_at and
          other_ends_at <= slot_ends_at
      ):
          return True
      return False
docs: Return boolean: whether or not two events overlap