Support for the Ruby 2.4 series has ended. See here for reference.
ItemBase
# File rss/maker/1.0.rb, line 234 def to_feed(rss) set_default_values do item = RDF::Item.new(link) set = setup_values(item) if set item.dc_dates.clear rss.items << item set_parent(item, rss) setup_other_elements(rss, item) elsif !have_required_values? raise NotSetError.new("maker.item", not_set_required_variables) end end end