categories_sellers_a1:
  seller_id: 1
  category_id: 1 # Category 1
categories_sellers_b1:
  seller_id: 1
  category_id: 2 # Category 2
categories_sellers_extra1:
  seller_id: 1
  category_id: 3 # A category from the remaining categories
categories_sellers_a2:
  seller_id: 2
  category_id: 1 # Category 1
categories_sellers_b2:
  seller_id: 2
  category_id: 2 # Category 2
categories_sellers_extra2:
  seller_id: 2
  category_id: 3 # A category from the remaining categories
<% 3.upto(20) do |num| %>
<%="categories_sellers_a#{num}:" %>
  seller_id: <%= num %>
  category_id: 1 # Category 1
<%="categories_sellers_b#{num}:" %>
  seller_id: <%= num %>
  category_id: 2 # Category 2
<%="categories_sellers_extra#{num}:" %>
  seller_id: <%= num %>
  category_id: <%= num %> # A category from the remaining categories
<% end %>