Link to PagingWithNetworkSample in docs

Test: ./gradlew createFlatfootDocsArchive -PofflineDocs=true

Change-Id: I7e310f159f3ac388a6e4243535fb69e3bc529bb3
diff --git a/paging/common/src/main/java/android/arch/paging/ItemKeyedDataSource.java b/paging/common/src/main/java/android/arch/paging/ItemKeyedDataSource.java
index 5fb999b..b113af4 100644
--- a/paging/common/src/main/java/android/arch/paging/ItemKeyedDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/ItemKeyedDataSource.java
@@ -29,6 +29,12 @@
  * Implement a DataSource using ItemKeyedDataSource if you need to use data from item {@code N - 1}
  * to load item {@code N}. This is common, for example, in sorted database queries where
  * attributes of the item such just before the next query define how to execute it.
+ * <p>
+ * The {@code InMemoryByItemRepository} in the
+ * <a href="https://github.com/googlesamples/android-architecture-components/blob/master/PagingWithNetworkSample/README.md">PagingWithNetworkSample</a>
+ * shows how to implement a network ItemKeyedDataSource using
+ * <a href="https://square.github.io/retrofit/">Retrofit</a>, while
+ * handling swipe-to-refresh, network errors, and retry.
  *
  * @param <Key> Type of data used to query Value types out of the DataSource.
  * @param <Value> Type of items being loaded by the DataSource.
diff --git a/paging/common/src/main/java/android/arch/paging/PageKeyedDataSource.java b/paging/common/src/main/java/android/arch/paging/PageKeyedDataSource.java
index 5df12e5..c12df3d 100644
--- a/paging/common/src/main/java/android/arch/paging/PageKeyedDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/PageKeyedDataSource.java
@@ -30,6 +30,12 @@
  * Implement a DataSource using PageKeyedDataSource if you need to use data from page {@code N - 1}
  * to load page {@code N}. This is common, for example, in network APIs that include a next/previous
  * link or key with each page load.
+ * <p>
+ * The {@code InMemoryByPageRepository} in the
+ * <a href="https://github.com/googlesamples/android-architecture-components/blob/master/PagingWithNetworkSample/README.md">PagingWithNetworkSample</a>
+ * shows how to implement a network PageKeyedDataSource using
+ * <a href="https://square.github.io/retrofit/">Retrofit</a>, while
+ * handling swipe-to-refresh, network errors, and retry.
  *
  * @param <Key> Type of data used to query Value types out of the DataSource.
  * @param <Value> Type of items being loaded by the DataSource.
diff --git a/paging/common/src/main/java/android/arch/paging/PagedList.java b/paging/common/src/main/java/android/arch/paging/PagedList.java
index 4bc9aa0..c6de5c5 100644
--- a/paging/common/src/main/java/android/arch/paging/PagedList.java
+++ b/paging/common/src/main/java/android/arch/paging/PagedList.java
@@ -928,6 +928,12 @@
      * passed, since it may not be fully computed by the DataSource if placeholders are not
      * supplied. Keys are not known because the BoundaryCallback is independent of the
      * DataSource-specific keys, which may be different for local vs remote storage.
+     * <p>
+     * The database + network Repository in the
+     * <a href="https://github.com/googlesamples/android-architecture-components/blob/master/PagingWithNetworkSample/README.md">PagingWithNetworkSample</a>
+     * shows how to implement a network BoundaryCallback using
+     * <a href="https://square.github.io/retrofit/">Retrofit</a>, while
+     * handling swipe-to-refresh, network errors, and retry.
      *
      * @param <T> Type loaded by the PagedList.
      */