Support for the Ruby 2.4 series has ended. See here for reference.
# File rss/image.rb, line 25 def validate_one_tag_name(ignore_unknown_element, name, tags) if !ignore_unknown_element invalid = tags.find {|tag| tag != name} raise UnknownTagError.new(invalid, IMAGE_URI) if invalid end raise TooMuchTagError.new(name, tag_name) if tags.size > 1 end