code: def generate_sections(self):
          
          sources = Dataset.objects.values(
              'source', 'source_slug'
          ).annotate(source_count=Count('source_slug'))
  
          return sorted([
              {
                  'slug': source['source_slug'],
                  'name': source['source'],
                  'count': source['source_count']
              }
              for source in sources
          ], key=lambda k: k['count'], reverse=True)
docs: Return dictionary of source section slugs, name, and counts.