Support for the Ruby 2.4 series has ended. See here for reference.
ChannelBase
# File rss/maker/1.0.rb, line 31 def to_feed(rss) set_default_values do _not_set_required_variables = not_set_required_variables if _not_set_required_variables.empty? channel = RDF::Channel.new(@about) setup_values(channel) channel.dc_dates.clear rss.channel = channel set_parent(channel, rss) setup_items(rss) setup_image(rss) setup_textinput(rss) setup_other_elements(rss, channel) else raise NotSetError.new("maker.channel", _not_set_required_variables) end end end