diff --git a/azure-client-runtime/src/main/java/com/microsoft/azure/AzureClient.java b/azure-client-runtime/src/main/java/com/microsoft/azure/AzureClient.java
index dfee2252e40bb..6529375f6343c 100644
--- a/azure-client-runtime/src/main/java/com/microsoft/azure/AzureClient.java
+++ b/azure-client-runtime/src/main/java/com/microsoft/azure/AzureClient.java
@@ -9,16 +9,6 @@
 
 import com.microsoft.rest.ServiceResponse;
 import com.microsoft.rest.ServiceResponseWithHeaders;
-import okhttp3.ResponseBody;
-import retrofit2.Response;
-import retrofit2.http.GET;
-import retrofit2.http.Header;
-import retrofit2.http.Url;
-import rx.Observable;
-import rx.Statement;
-import rx.functions.Action0;
-import rx.functions.Func0;
-import rx.functions.Func1;
 
 import java.io.IOException;
 import java.lang.reflect.Type;
@@ -29,6 +19,14 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
+import okhttp3.ResponseBody;
+import retrofit2.Response;
+import retrofit2.http.GET;
+import retrofit2.http.Header;
+import retrofit2.http.Url;
+import rx.Observable;
+import rx.functions.Func1;
+
 /**
  * An instance of this class defines a ServiceClient that handles polling and
  * retrying for long running operations when accessing Azure resources.
diff --git a/azure-client-runtime/src/main/java/com/microsoft/azure/AzureServiceCall.java b/azure-client-runtime/src/main/java/com/microsoft/azure/AzureServiceCall.java
index 2d311bc0b7125..d60604815046e 100644
--- a/azure-client-runtime/src/main/java/com/microsoft/azure/AzureServiceCall.java
+++ b/azure-client-runtime/src/main/java/com/microsoft/azure/AzureServiceCall.java
@@ -12,7 +12,6 @@
 
 import rx.Observable;
 import rx.Subscriber;
-import rx.functions.Action1;
 import rx.functions.Func1;
 
 /**
@@ -22,48 +21,75 @@
  *
  * @param <T> the type of the returning object
  */
-public class AzureServiceCall<T> extends ServiceCall<T> {
+public final class AzureServiceCall<T> extends ServiceCall<T> {
     private AzureServiceCall() {
     }
 
+    /**
+     * Creates a ServiceCall from a paging operation.
+     *
+     * @param first the observable to the first page
+     * @param next the observable to poll subsequent pages
+     * @param callback the client-side callback
+     * @param <T> the Page type
+     * @param <V> the element type
+     * @return the future based ServiceCall
+     */
     public static <T extends Page<V>, V> ServiceCall<T> create(Observable<ServiceResponse<T>> first, final Func1<String, Observable<ServiceResponse<T>>> next, final ListOperationCallback<V> callback) {
         final AzureServiceCall<T> serviceCall = new AzureServiceCall<>();
-        final Subscriber<ServiceResponse<T>> subscriber = new Subscriber<ServiceResponse<T>>() {
-            private ServiceResponse<T> lastResponse;
+        final PagingSubscriber<T, V> subscriber = new PagingSubscriber<>(serviceCall, next, callback);
+        serviceCall.setSubscription(first
+            .single()
+            .subscribe(subscriber));
+        return serviceCall;
+    }
 
-            @Override
-            public void onCompleted() {
-                // do nothing
-            }
+    /**
+     * The subscriber that handles user callback and automatically subscribes to the next page.
+     *
+     * @param <T> the Page type
+     * @param <V> the element type
+     */
+    private static class PagingSubscriber<T extends Page<V>, V> extends Subscriber<ServiceResponse<T>> {
+        private AzureServiceCall<T> serviceCall;
+        private Func1<String, Observable<ServiceResponse<T>>> next;
+        private ListOperationCallback<V> callback;
+        private ServiceResponse<T> lastResponse;
 
-            @Override
-            public void onError(Throwable e) {
-                serviceCall.setException(e);
-                if (callback != null) {
-                    callback.failure(e);
-                }
+        PagingSubscriber(final AzureServiceCall<T> serviceCall, final Func1<String, Observable<ServiceResponse<T>>> next, final ListOperationCallback<V> callback) {
+            this.serviceCall = serviceCall;
+            this.next = next;
+            this.callback = callback;
+        }
+
+        @Override
+        public void onCompleted() {
+            // do nothing
+        }
+
+        @Override
+        public void onError(Throwable e) {
+            serviceCall.setException(e);
+            if (callback != null) {
+                callback.failure(e);
             }
+        }
 
-            @Override
-            public void onNext(ServiceResponse<T> serviceResponse) {
-                lastResponse = serviceResponse;
-                ListOperationCallback.PagingBehavior behavior = ListOperationCallback.PagingBehavior.CONTINUE;
-                if (callback != null) {
-                    behavior = callback.progress(serviceResponse.getBody().getItems());
-                    if (behavior == ListOperationCallback.PagingBehavior.STOP || serviceResponse.getBody().getNextPageLink() == null) {
-                        callback.success();
-                    }
-                }
+        @Override
+        public void onNext(ServiceResponse<T> serviceResponse) {
+            lastResponse = serviceResponse;
+            ListOperationCallback.PagingBehavior behavior = ListOperationCallback.PagingBehavior.CONTINUE;
+            if (callback != null) {
+                behavior = callback.progress(serviceResponse.getBody().getItems());
                 if (behavior == ListOperationCallback.PagingBehavior.STOP || serviceResponse.getBody().getNextPageLink() == null) {
-                    serviceCall.set(lastResponse);
-                } else {
-                    serviceCall.setSubscription(next.call(serviceResponse.getBody().getNextPageLink()).single().subscribe(subscriber));
+                    callback.success();
                 }
             }
-        };
-        serviceCall.setSubscription(first
-            .single()
-            .subscribe(subscriber));
-        return serviceCall;
+            if (behavior == ListOperationCallback.PagingBehavior.STOP || serviceResponse.getBody().getNextPageLink() == null) {
+                serviceCall.set(lastResponse);
+            } else {
+                serviceCall.setSubscription(next.call(serviceResponse.getBody().getNextPageLink()).single().subscribe(this));
+            }
+        }
     }
 }
diff --git a/azure-client-runtime/src/main/java/com/microsoft/azure/ListOperationCallback.java b/azure-client-runtime/src/main/java/com/microsoft/azure/ListOperationCallback.java
index 9c193b69f464e..63dc60f9f7c6b 100644
--- a/azure-client-runtime/src/main/java/com/microsoft/azure/ListOperationCallback.java
+++ b/azure-client-runtime/src/main/java/com/microsoft/azure/ListOperationCallback.java
@@ -75,6 +75,9 @@ public void success(ServiceResponse<List<E>> result) {
         success();
     }
 
+    /**
+     * Override this method to handle successful REST call results.
+     */
     public abstract void success();
 
     /**
diff --git a/azure-client-runtime/src/main/java/com/microsoft/azure/PagedList.java b/azure-client-runtime/src/main/java/com/microsoft/azure/PagedList.java
index f965a5581cd8b..4f966acbcf3d0 100644
--- a/azure-client-runtime/src/main/java/com/microsoft/azure/PagedList.java
+++ b/azure-client-runtime/src/main/java/com/microsoft/azure/PagedList.java
@@ -9,8 +9,6 @@
 
 import com.microsoft.rest.RestException;
 
-import javax.xml.bind.DataBindingException;
-import javax.xml.ws.WebServiceException;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -19,6 +17,8 @@
 import java.util.ListIterator;
 import java.util.NoSuchElementException;
 
+import javax.xml.bind.DataBindingException;
+
 /**
  * Defines a list response from a paging operation. The pages are
  * lazy initialized when an instance of this class is iterated.
diff --git a/client-runtime/src/main/java/com/microsoft/rest/ServiceCall.java b/client-runtime/src/main/java/com/microsoft/rest/ServiceCall.java
index 53cb4e22ffcb5..0d97464beeae7 100644
--- a/client-runtime/src/main/java/com/microsoft/rest/ServiceCall.java
+++ b/client-runtime/src/main/java/com/microsoft/rest/ServiceCall.java
@@ -99,7 +99,7 @@ public Subscription getSubscription() {
         return subscription;
     }
 
-    protected void setSubscription(Subscription subscription) {
+    public void setSubscription(Subscription subscription) {
         this.subscription = subscription;
     }