Add Route#withDocString(DocString)

apollo-api/src/main/java/com/spotify/apollo/route/Route.java

@@ -60,6 +60,11 @@ default Route<H> withDocString(String summary, String description) {
         method(), uri(), handler(), doc(summary, description));
   }
 
+  default Route<H> withDocString(DocString doc) {
+    return copy(
+        method(), uri(), handler(), doc);
+  }
+
   default <K> Route<K> withMiddleware(Middleware<? super H, ? extends K> middleware) {
     return copy(
         method(), uri(), middleware.apply(handler()), docString().orElse(null));

apollo-api/src/test/java/com/spotify/apollo/route/RouteTest.java

@@ -20,10 +20,13 @@
 package com.spotify.apollo.route;
 
 import com.spotify.apollo.RequestContext;
+import com.spotify.apollo.route.Route.DocString;
 
 import org.junit.Before;
 import org.junit.Test;
 
+import java.util.Optional;
+
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
@@ -45,4 +48,13 @@ public void shouldSupportSyncEndpointHandler() throws Exception {
     String actual = route.handler().invoke(requestContext).toCompletableFuture().get();
     assertThat(actual, equalTo("this is the best response"));
   }
+
+  @Test
+  public void shouldSupportSupplyingDocStringValueType() throws Exception {
+    Route<AsyncHandler<String>> route =
+        Route.sync("GET", "/foo", requestContext -> "this is the best response")
+            .withDocString(DocString.doc("summary", "description"));
+
+    assertThat(route.docString(), equalTo(Optional.of(DocString.doc("summary", "description"))));
+  }
 }