in src/main/java/org/apache/sling/auth/xing/oauth/impl/XingOauthLoginModulePlugin.java [75:81]
public boolean canHandle(final Credentials credentials) {
logger.debug("canHandle({})", credentials);
final Token accessToken = XingOauthUtil.getAccessToken(credentials);
final XingUser xingUser = XingOauthUtil.getXingUser(credentials);
logger.debug("access token: {}, xing user: {}", accessToken, xingUser);
return accessToken != null && xingUser != null;
}