doc for downloadSource of data overlay API call

web/src/test/java/lcsb/mapviewer/web/OverlayControllerIntegrationTest.java

@@ -822,10 +822,13 @@ public class OverlayControllerIntegrationTest extends ControllerIntegrationTest
 
     MockHttpSession session = createSession(BUILT_IN_TEST_ADMIN_LOGIN, BUILT_IN_TEST_ADMIN_PASSWORD);
 
-    RequestBuilder request = get("/projects/" + TEST_PROJECT + "/overlays/" + overlay.getId() + ":downloadSource")
-        .session(session);
+    RequestBuilder request = get("/projects/{projectId}/overlays/{overlayId}:downloadSource", TEST_PROJECT,
+        overlay.getId())
+            .session(session);
 
     mockMvc.perform(request)
+        .andDo(document("projects/project_overlays/download_source",
+            getOverlayPathParameters()))
         .andExpect(status().is2xxSuccessful());
   }