public String authorization() {
        if (authorization == null) {
            final String type = (tokenType == null) ? DEFAULT_TOKEN_TYPE : tokenType;
            authorization = CaseUtil.firstUpperAllLowerCase(type) + AUTHORIZATION_SEPARATOR + accessToken;
        }
        return authorization;
    }
A value of the {@link HttpHeaderNames#AUTHORIZATION} header based on this access token.
oauth2/src/main/java/com/linecorp/armeria/common/auth/oauth2/GrantedOAuth2AccessToken.java