module Playbook::NumberSpacing

def number_spacing_props
  selected_index_props = number_spacing_options.keys.select { |sk| try(sk) }
  return nil unless selected_index_props.present?
  selected_index_props.map do |k|
    index_value = send(k)
    "ns_#{index_value}" if number_spacing_values.include? index_value
  end.compact.join(" ")
end