def find_or_build_page_part(attr_name)
      key = normalize_page_part_key(attr_name)
      page_parts.detect { |record| record.key.to_s == key } || page_parts.build(key: key)
    end
def find_or_build_page_part(attr_name)
      key = normalize_page_part_key(attr_name)
      page_parts.detect { |record| record.key.to_s == key } || page_parts.build(key: key)
    end
Find page part by key or build new record