Add derived next cursor support

Author: adimiz1

cloudinary-core/src/main/java/com/cloudinary/Api.java

@@ -200,7 +200,7 @@ public ApiResponse resource(String public_id, Map options) throws Exception {
         ApiResponse response = callApi(HttpMethod.GET, Arrays.asList("resources", resourceType, type, public_id),
                 ObjectUtils.only(options, "exif", "colors", "faces", "coordinates",
                         "image_metadata", "pages", "phash", "max_results", "quality_analysis", "cinemagraph_analysis",
-                        "accessibility_analysis", "versions", "media_metadata"), options);
+                        "accessibility_analysis", "versions", "media_metadata", "derived_next_cursor"), options);
 
         return response;
     }

cloudinary-test-common/src/main/java/com/cloudinary/test/AbstractApiTest.java

@@ -1305,4 +1305,29 @@ public void testDeleteBackedupAsset() throws Exception {
             assertEquals(deletedVersionIds.get(0), firstAssetVersion);
         }
     }
+
+    @Test
+    public void testAllowDerivedNextCursor() throws Exception {
+        String publicId = "allowderivednextcursor_" + SUFFIX;
+        Map options = ObjectUtils.asMap("public_id", publicId, "eager", Arrays.asList(
+                new Transformation().width(100),
+                new Transformation().width(101),
+                new Transformation().width(102)
+        ));
+
+        try {
+            cloudinary.uploader().upload(SRC_TEST_IMAGE, options);
+            ApiResponse res = api.resource(publicId, Collections.singletonMap("max_results", 1));
+            String derivedNextCursor = res.get("derived_next_cursor").toString();
+            assertNotNull(derivedNextCursor);
+
+            ApiResponse res2 = api.resource(publicId, ObjectUtils.asMap("derived_next_cursor", derivedNextCursor, "max_results", 1));
+            String derivedNextCursor2 = res2.get("derived_next_cursor").toString();
+            assertNotNull(derivedNextCursor2);
+
+            assertNotEquals(derivedNextCursor, derivedNextCursor2);
+        } finally {
+            cloudinary.uploader().destroy(publicId, Collections.singletonMap("invalidate", true));
+        }
+    }
 }