public static final AuthToken createAuthToken(String principal, Set<String> roles, int expiresInMillis) {
        AuthToken token = new AuthToken();
        token.setIssuedOn(new Date());
        token.setExpiresOn(new Date(System.currentTimeMillis() + expiresInMillis));
        token.setPrincipal(principal);
        token.setRoles(roles);
        signAuthToken(token);
        return token;
    }
Creates an auth token.
@param principal the auth principal
@param roles the auth roles
@param expiresInMillis the number of millis to expiry
@return the auth token
common/auth/src/main/java/io/apiman/common/auth/AuthTokenUtil.java