How to remove PreferenceCategory programmatically?

I need to remove a PreferenceCategory programmatically. I could remove the individual preferences with the following code but I need to remove (disable) whole PreferenceCategory as well.

PreferenceScreen preferenceScreen = getPreferenceScreen();
EditTextPreference etp = (EditTextPreference) preferenceScreen.findPreference("pref22");
((PreferenceGroup) findPreference("prefcat")).removePreference(etp);

Edit: Here's the working code for a PreferenceCategory "prefcat" and a child preference "pref22":

PreferenceScreen preferenceScreen = getPreferenceScreen();
EditTextPreference etp = (EditTextPreference) preferenceScreen.findPreference("pref22");

PreferenceGroup preferenceGroup = (PreferenceGroup) findPreference("prefcat");
if (preferenceGroup != null) {
    preferenceGroup.removePreference(etp);
    preferenceScreen.removePreference(preferenceGroup);
}