What is IRetryAnalyzer in TestNG and how do you implement it?

import org.testng.IRetryAnalyzer;
import org.testng.ITestResult;

public class RetryAnalyzer implements IRetryAnalyzer {
    private int retryCount = 0;
    private static final int MAX_RETRY = 2; // retry up to 2 times (3 total attempts)

    @Override
    public boolean retry(ITestResult result) {
        if (retryCount < MAX_RETRY) {
            System.out.println("Retrying test: " + result.getName()
                + " | Attempt: " + (retryCount + 1));
            retryCount++;
            return true;  // retry
        }
        return false; // stop retrying
    }
}

@Test(retryAnalyzer = RetryAnalyzer.class)
public void flakeyLoginTest() {
    // If this fails, TestNG retries up to 2 more times
    Assert.assertTrue(driver.getTitle().contains("Dashboard"));
}

import org.testng.IAnnotationTransformer;
import org.testng.annotations.ITestAnnotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

public class RetryListener implements IAnnotationTransformer {

    @Override
    public void transform(ITestAnnotation annotation, Class testClass,
                          Constructor testConstructor, Method testMethod) {
        // Apply RetryAnalyzer to every @Test method automatically
        annotation.setRetryAnalyzer(RetryAnalyzer.class);
    }
}

<suite name="Suite">
    <listeners>
        <listener class-name="listeners.RetryListener"/>
    </listeners>
    <test name="Tests">
        <classes>
            <class name="tests.LoginTest"/>
        </classes>
    </test>
</suite>

public class RetryReportListener implements ITestListener {

    @Override
    public void onTestSkipped(ITestResult result) {
        // If skip was caused by retry, remove from skipped count
        if (result.getMethod().getRetryAnalyzerClass() != null) {
            Reporter.log(result.getName() + " was retried, not truly skipped");
            // Can also programmatically remove from reporter
        }
    }
}

Test FAILS on attempt 1  → retry() returns true  → attempt 2
Test FAILS on attempt 2  → retry() returns true  → attempt 3
Test FAILS on attempt 3  → retry() returns false → FAIL recorded
OR
Test PASSES on attempt 2 → no more retries       → PASS recorded