title: What is "lookup" argument of NestedSimpleRouter class?
body: <p>I'm using <a href="https://github.com/alanjds/drf-nested-routers" rel="nofollow noreferrer">drf-nested-routers</a> to create several nested API endpoints.</p>
  <p>Let's take a look at the next piece of code in my <strong>routes.py</strong> file:</p>
  <pre><code>from rest_framework_nested.routers import SimpleRouter, NestedSimpleRoute
  
  base_router = SimpleRouter()
  base_router.register(&quot;categories&quot;, CategoryModelView)
  
  dishes_types_router = NestedSimpleRouter(base_router, r&quot;categories&quot;, lookup=&quot;category&quot;)
  dishes_types_router.register(r&quot;types_of_dishes&quot;, DishesTypeModelView, basename=&quot;dishes_type&quot;)
  </code></pre>
  <p><strong>My question is</strong>: what does <code>lookup=&quot;category&quot;</code> in the fourth row do?</p>