code: @Override
      public int getSectionForPosition(int position) {
          Object[] objects = getSections(); // the fast scroll section objects
          int sectionIndex = getIndexWithinSections(position);
  
          return sectionIndex < objects.length ? sectionIndex : 0;
      }
docs: Given a position within the adapter, returns the index of the
  corresponding section within the array of section objects.
  
  If the section index is outside of the section array bounds, the index
  must be clipped to fall within the size of the section array.
  
  For example, consider an indexer where the section at array index 0
  starts at adapter position 100. Calling this method with position 10,
  which is before the first section, must return index 0.
  
  @param position the position within the adapter for which to return the
  corresponding section index
  @return the index of the corresponding section within the array of
  section objects, constrained to fall within the array bounds