public void toggleSectionItemSelected(int sectionIndex, int itemIndex) {
        setSectionItemSelected(sectionIndex, itemIndex, !isSectionItemSelected(sectionIndex, itemIndex));
    }
Toggle selection state of a specific item in a section

@param sectionIndex index of section
@param itemIndex    index of item in section
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/section/SectioningAdapter.java