How can this be wrong argument?

I have tried to solve this, but Android Studio keeps faulting this line in my code. When I run the Bignerdranch chapter code, the app will load to the emulator and run, but lint still highlights the methods in red.

Any suggestions as to how I made this error or can fix it?

Please check whether your CrimeFragment extends Fragment (android.support.v4.app.Fragment)

Thank you, but My imports have worked unchanged, just until I added the setTargetFragment() method.

SOLVED: My DatePickerFragment.java extended DialogFragment, but when I checked it had the option to used .v4.app.DialogFragment it fixed the issue.

NEW extends for DatePickerFragment.java

public class DatePickerFragment extends android.support.v4.app.DialogFragment {

So to be clear: When I added DataPickerFragement.java the extends keyword offers two support opptions: android.app.DialogFragment and android.support.v4.app.DialogFragment.

My failure was not checking to verify the match to the other class files

I now know to make sure that all my fragments use the .v4.app support libraries across all class files.

The book makes this clear on page 230.