code: def add_block_options(self, top):
          
          from .blockadmin import blocks
  
          block_choices = []
  
          # Group all block by category
          for category in sorted(blocks.site.block_list):
              category_blocks = blocks.site.block_list[category]
              category_choices = []
  
              for block in category_blocks:
                  base_url = reverse('block_admin:{}_{}_add'.format(
                      block._meta.app_label, block._meta.model_name,
                  ), kwargs={
                      'version_id': self.glitter_page.version.id,
                  })
                  block_qs = {
                      'column': self.name,
                      'top': top,
                  }
                  block_url = '{}?{}'.format(base_url, urlencode(block_qs))
                  block_text = capfirst(force_text(block._meta.verbose_name))
  
                  category_choices.append((block_url, block_text))
  
              category_choices = sorted(category_choices, key=lambda x: x[1])
              block_choices.append((category, category_choices))
  
          return block_choices
docs: Return a list of URLs and titles for blocks which can be added to this column.
  
          All available blocks are grouped by block category.