public int getAdapterPositionForSectionHeader(int sectionIndex) {
        if (doesSectionHaveHeader(sectionIndex)) {
            return getAdapterPosition(sectionIndex, 0);
        } else {
            return NO_POSITION;
        }
    }
Return the adapter position corresponding to the header of the provided section

@param sectionIndex the index of the section
@return adapter position of that section's header, or NO_POSITION if section has no header
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/section/SectioningAdapter.java