Adds a proxy overload for SdkIterable calls (#190)

AWS' Java SDK v2 introduces SdkIterable responses as a clean way to interact with paginated APIs and this change adds an interface to the AmazonWebServicesClientProxy class to invoke these.

Author: RJ Lohan

src/main/java/com/amazonaws/cloudformation/proxy/AmazonWebServicesClientProxy.java

@@ -44,6 +44,7 @@
 import software.amazon.awssdk.awscore.exception.AwsErrorDetails;
 import software.amazon.awssdk.awscore.exception.AwsServiceException;
 import software.amazon.awssdk.core.exception.NonRetryableException;
+import software.amazon.awssdk.core.pagination.sync.SdkIterable;
 import software.amazon.awssdk.http.HttpStatusCode;
 
 /**
@@ -350,6 +351,24 @@ public final long getRemainingTimeInMillis() {
         }
     }
 
+    public <RequestT extends AwsRequest, ResultT extends AwsResponse, IterableT extends SdkIterable<ResultT>>
+        IterableT
+        injectCredentialsAndInvokeIterableV2(final RequestT request, final Function<RequestT, IterableT> requestFunction) {
+
+        AwsRequestOverrideConfiguration overrideConfiguration = AwsRequestOverrideConfiguration.builder()
+            .credentialsProvider(v2CredentialsProvider).build();
+
+        @SuppressWarnings("unchecked")
+        RequestT wrappedRequest = (RequestT) request.toBuilder().overrideConfiguration(overrideConfiguration).build();
+
+        try {
+            return requestFunction.apply(wrappedRequest);
+        } catch (final Throwable e) {
+            loggerProxy.log(String.format("Failed to execute remote function: {%s}", e.getMessage()));
+            throw e;
+        }
+    }
+
     public <RequestT, ClientT, ModelT, CallbackT extends StdCallbackContext>
         ProgressEvent<ModelT, CallbackT>
         defaultHandler(RequestT request, Exception e, ClientT client, ModelT model, CallbackT context) {