如何使用Java“漂亮地打印”或“转储”opensaml断言对象？

import org.opensaml.core.xml.io.MarshallingException;
import org.opensaml.saml.saml2.core.Assertion;
import org.opensaml.saml.saml2.core.impl.AssertionMarshaller;
import org.opensaml.xmlsec.signature.support.SignatureException;

public class OpenSamlAssertionPrinter {
    public static void main(String[] args) {
        // 创建断言对象
        Assertion assertion = createAssertion();

        // 初始化 opensaml
        try {
            DefaultBootstrap.bootstrap();
        } catch (ConfigurationException e) {
            e.printStackTrace();
        }

        // 打印或转储断言对象
        try {
            AssertionMarshaller marshaller = new AssertionMarshaller();
            String assertionString = marshaller.marshall(assertion);
            System.out.println(assertionString);
        } catch (MarshallingException e) {
            e.printStackTrace();
        }
    }

    private static Assertion createAssertion() {
        // 创建并返回断言对象
        // 这里省略具体实现
        return null;
    }
}