code: public static Optional<Principal> withWebIdClaim(final Claims claims) {
          final String webid = claims.get(WEBID, String.class);
          if (webid == null) return empty();
          LOGGER.debug("Using JWT claim with webid: {}", webid);
          return of(new OAuthPrincipal(webid));
      }
docs: Generate a Principal from a webid claim.
  @param claims the JWT claims
  @return a Principal, if one can be generated from a webid claim