# File lib/html/pipeline/sanitization_filter.rb, line 126
      def whitelist
        whitelist = context[:whitelist] || WHITELIST
        anchor_schemes = context[:anchor_schemes]
        return whitelist unless anchor_schemes
        whitelist = whitelist.dup
        whitelist[:protocols] = (whitelist[:protocols] || {}).dup
        whitelist[:protocols]['a'] = (whitelist[:protocols]['a'] || {}).merge('href' => anchor_schemes)
        whitelist
      end