title: Automatically document @PathVariable annotated parameters within @ModelAttribute annotated methods
body: <p>In our REST-API we need to be multi-tenant capable. For achiving this all rest controllers subclass a common REST controller which defines a request mapping prefix and exposes a model attribute as follows</p>
  
  <pre><code>@RequestMapping(path = "/{tenantKey}/api")
  public class ApiController {
  
     @ModelAttribute
     public Tenant getTenant(@PathVariable("tenantKey") String tenantKey) {
       return repository.findByTenantKey(tenantKey);
     }
  
  }
  </code></pre>
  
  <p>Derived controllers make use of the model attributes in their request mapping methods:</p>
  
  <pre><code>@RestController
  public class FooController extends ApiController {
  
    @RequestMapping(value = "/foo", method = GET)
    public List&lt;Foo&gt; getFoo(@ApiIgnore @ModelAttribute Tenant tenant) {
      return service.getFoos(tenant);
    }
  
  }
  </code></pre>
  
  <p>This endpoint gets well documented in the swagger-ui. I get an endpoint documented with a GET mapping for path <code>/{tenantKey}/api/foo</code>.</p>
  
  <p>My issue is, that the {tenantKey}  path variable is not documented in swagger-ui as parameter. The parameters section in swagger is not rendered at all. If I add a String parameter to controller method, annotating it with <code>@PathVariable("tenantKey)</code> everything is fine, but I don't want a <code>tenantKey</code> parameter in my controller method, since the resolved tenant is already available as model attribute.</p>
  
  <p>So my question is: Is there a way do get the <code>@PathVariable</code> from the <code>@ModelAttriute</code> annotated method in <code>ApiController</code> documented within swagger-ui in this setup?</p>
  
  <p>Project-Setup is</p>
  
  <ul>
  <li>Spring-Boot (1.4.2)</li>
  <li>springfox-swagger2 (2.6.1)</li>
  <li>springfox-swagger-ui (2.6.1)</li>
  </ul>