def content_encoding
      vs = @metas['content-encoding']
      if vs && %r{\A#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?(?:,#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?)*}o =~ (v = vs.join(', '))
        v.scan(RE_TOKEN).map {|content_coding| content_coding.downcase}
      else
        []
      end
    end
def content_encoding
      vs = @metas['content-encoding']
      if vs && %r{\A#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?(?:,#{RE_LWS}?#{RE_TOKEN}#{RE_LWS}?)*}o =~ (v = vs.join(', '))
        v.scan(RE_TOKEN).map {|content_coding| content_coding.downcase}
      else
        []
      end
    end
Returns a list of encodings in Content-Encoding field as an array of
 strings.

 The encodings are downcased for canonicalization.