where_is_yadis? (OpenID::Yadis)

    # File lib/openid/yadis/discovery.rb, line 124
        def self.where_is_yadis?(resp)
          # Attempt to find out where to go to discover the document or if
          # we already have it
          content_type = resp['content-type']

          # According to the spec, the content-type header must be an
          # exact match, or else we have to look for an indirection.
          if (!content_type.nil? and
              content_type.split(';', 2)[0].downcase == YADIS_CONTENT_TYPE)
            return resp.final_url
          else
            # Try the header
            yadis_loc = resp[YADIS_HEADER_NAME.downcase]

            if yadis_loc.nil?
              # Parse as HTML if the header is missing.
              #
              # XXX: do we want to do something with content-type, like
              # have a whitelist or a blacklist (for detecting that it's
              # HTML)?
              yadis_loc = Yadis.html_yadis_location(resp.body)
            end
          end

          return yadis_loc
        end