Fluent API with inheritance for validators - input validator instance seems identified as parent class

Question

I'm writing a fluent API to validate key:value pair in a Map. I have a hierarchy of validator types. I referred to one answer from Fluent API with inheritance and generics.

public interface IValidator {
    IValidator assertValue(String key, String expectedValue) throws Exception;

    abstract class Abstract implements IValidator {

        protected final Map<String, String> resultMap = new HashMap<>();

        @Override
        public <T extends IValidator> T assertValue(String key, String expectedValue) throws Exception {
            ...
            return (T) this;
    }
}

The 2nd level abstract subclasses redefine the parent type as follows.

public abstract class AbstractValidator
extends IValidator.Abstract {
    // other logic not related to assertion
}

The concrete subclasses redefine the parent type similarly.

public class ExampleValidator
extends AbstractValidator
{
    public ExampleValidator assertPromptId(String expectedValue) throws Exception{
        assertValue(PROMPT_ID, expectedValue);
        return  this;
    }

    public ExampleValidator assertNameSpace(String expectedValue ) throws Exception{
        assertValue(NAMESPACE, expectedValue);
        return this;
    }

    @Override
    public ExampleValidator assertValue(String key, String  expectedVlaue) throws Exception {
        super.assertValue(key, expectedVlaue);
        return this;
    }

Now, my test case is as follows. My issue is .withValidator(Ivalidator validator) was not able to find method of assertPromptId() and assertNameSpace() but only assertValue(). So how to fix it?

public class AssertionContext {
    public <T extends IValidator> T withValidator(IValidator validator) throws Exception {
        return (T) validator;
    }
} 

// test method in main
public void invocationTest() throws Throwable {
        AssertionContext verify = new AssertionContext();
        verify.withValidator(new ExampleValidator()).assertNameSpace("...");
    }

Answer 1

Actually I found the solution is very simple.

public <T extends IValidator> T withValidator(T t) throws Exception {
    ...
    return t;
}