Handling Exceptions that occour during chained methods calls using PowerMock

I have a class which I would like to test with a public static method that contains some chained method calls. Assuming that an exception occurs during the chained method calls, how do I handle this effectively?

Following is the code sample of the test class.

@RunWith(PowerMockRunner.class)

@PrepareForTest({CodeWithPrivateMethod.class,CodeWithAnotherPrivateMethod.class,CodeWithYetAnotherPrivateMethod.class}) public class CodeWithPrivateMethodTest {

@Test
public void when_gambling_is_true_then_always_explode() throws Exception {


    CodeWithYetAnotherPrivateMethod codeWithYetAnotherPrivateMethod = PowerMockito.spy(new CodeWithYetAnotherPrivateMethod());
    PowerMockito.whenNew(CodeWithYetAnotherPrivateMethod.class).withAnyArguments().thenReturn(codeWithYetAnotherPrivateMethod);

    CodeWithAnotherPrivateMethod codeWithAnotherPrivateMethod = PowerMockito.spy(new CodeWithAnotherPrivateMethod());
    PowerMockito.whenNew(CodeWithAnotherPrivateMethod.class).withAnyArguments().thenReturn(codeWithAnotherPrivateMethod);

    PowerMockito.doReturn(true).when(codeWithYetAnotherPrivateMethod, "getGambling");

    //PowerMockito.doReturn(codeWithYetAnotherPrivateMethod).when(codeWithAnotherPrivateMethod, "getGambleValue");

    PowerMockito.spy(CodeWithPrivateMethod.class);
    CodeWithPrivateMethod.startGamble();

}

}

Following is the code sample for the class under test

public class CodeWithPrivateMethod {

public static void startGamble() {

    Boolean gamble = CodeWithAnotherPrivateMethod.getGambleValue()
            .getGambling();
    if (gamble) {
        System.out.println("kaboom");
    }else{
        System.out.println("boom boom");
    }
}

}

Following is the code sample for the class that gets called from the class under test

public class CodeWithAnotherPrivateMethod {

static CodeWithYetAnotherPrivateMethod codeWithYetAnotherPrivateMethod = new CodeWithYetAnotherPrivateMethod();


public static CodeWithYetAnotherPrivateMethod getGambleValue() {
    return codeWithYetAnotherPrivateMethod; //works fine
    return null; // fails
}

}

Following is the code sample for the other class that gets called from the class under test

public class CodeWithYetAnotherPrivateMethod {

public Boolean getGambling() {
    return false;
}

}

So Assuming I return a null value from getGambleValue() method of CodeWithAnotherPrivateMethod class, how do I handle this null value effectively in my testclass?