classes.rb

 classes = if update.classes?
    if update[:classes].include? "DELETE"
      nil
    elsif person['data']['classes'].nil? or person['data']['classes'].empty?
      update[:classes]
    else
      (person['data']['classes'] | update[:classes]).sort
    end
  else
    person['data']['classes']
  end


  classes = if Array(update[:classes]).include? "DELETE"
    nil
  else
    (Array(person['data']['classes']) | Array(update[:classes])).sort
  end