How to get variable value in extensionContext

How would I get the value of the result field into my TestReporter class?

@ExtendWith({TestReporter.class})
private TestClass{
   String result;
   
   @Test
   void testA(){
     //some action here
     result = some result;
   }
}

public class TestReporter implements BeforeAllCallback, BeforeTestExecutionCallback, AfterAllCallback,
       TestWatcher {
    private static ExtentHtmlReporter htmlReporter;
    private static ExtentReports extent;
    private static ExtentTest test;

    @Override
    public void beforeAll(ExtensionContext context) throws Exception {
       //set up extent report
    }


   @Override
   public void testSuccessful(ExtensionContext context) {
     //not possible, but desired
     test.pass(context.getElement.get("result"), MediaEntityBuilder.createScreenCaptureFromPath("test"+count+".png").build());

   }

}

I have been researching ways to do this but not sure if what Im looking for is even possible or how to implement

TLDR;

Use reflection in the extension that has to implement an appropriate callback, e.g. AfterEachCallback. Grab the instance of the test class through context.getRequiredTestInstance().

Long Version

@ExtendWith(TestReporter.class)
public class TestClass {

	String result;

	@Test
	void testA() {
		result = "some result";
	}
}

class TestReporter implements AfterEachCallback {
	@Override
	public void afterEach(final ExtensionContext context) throws Exception {
		Object testInstance = context.getRequiredTestInstance();

		Field resultField = testInstance.getClass().getDeclaredField("result");

		String resultValue = (String) resultField.get(testInstance);

		System.out.println("Value of result: " + resultValue);
	}
}

Mind that an AfterAllContext does NOT have access to the test instance because there is one instance per test method. Using TestWatcher instead of AfterEachCallback would also work.