# File lib/rss/content.rb, line 16
16:     def self.append_features(klass)
17:       super
18: 
19:       klass.install_must_call_validator(CONTENT_PREFIX, CONTENT_URI)
20:       %w(encoded).each do |name|
21:         klass.install_text_element(name, CONTENT_URI, "?",
22:                                    "#{CONTENT_PREFIX}_#{name}")
23:       end
24:     end