Support for the Ruby 2.4 series has ended. See here for reference.
Checks if there are duplicate links with the same type and hreflang attributes that have an alternate (or empty) rel attribute
Raises a TooMuchTagError if there are duplicates found
# File rss/atom.rb, line 249
def validate_duplicate_links(links)
link_infos = {}
links.each do |link|
rel = link.rel || "alternate"
next unless rel == "alternate"
key = [link.hreflang, link.type]
if link_infos.has_key?(key)
raise TooMuchTagError.new("link", tag_name)
end
link_infos[key] = true
end
end