Support getFollowers limit parameter (#715)

Author: tawAsh1

line-bot-api-client/src/main/java/com/linecorp/bot/client/LineMessagingClientImpl.java

@@ -318,7 +318,7 @@ public CompletableFuture<GetNumberOfFollowersResponse> getNumberOfFollowers(Stri
 
     @Override
     public CompletableFuture<GetFollowersResponse> getFollowers(GetFollowersRequest request) {
-        return toFuture(retrofitImpl.getFollowers(request.getNext()));
+        return toFuture(retrofitImpl.getFollowers(request.getNext(), request.getLimit()));
     }
 
     @Override

line-bot-api-client/src/main/java/com/linecorp/bot/client/LineMessagingService.java

@@ -384,7 +384,7 @@ Call<Void> linkRichMenuToUser(
      * Get a list of users who added your LINE Official Account as a friend.
      */
     @GET("v2/bot/followers/ids")
-    Call<GetFollowersResponse> getFollowers(@Query("start") String next);
+    Call<GetFollowersResponse> getFollowers(@Query("start") String next, @Query("limit") Integer limit);
 
     /**
      * Returns statistics about how users interact with narrowcast messages or broadcast messages sent from your

line-bot-api-client/src/test/java/com/linecorp/bot/client/LineMessagingClientImplTest.java

@@ -870,9 +870,9 @@ public void getFollowers() throws Exception {
                 .builder()
                 .userIds(ImmutableList.of("U1234"))
                 .build();
-        whenCall(retrofitMock.getFollowers(nullable(String.class)), response);
+        whenCall(retrofitMock.getFollowers(nullable(String.class), nullable(Integer.class)), response);
         final GetFollowersResponse actual = target.getFollowers(GetFollowersRequest.builder().build()).get();
-        verify(retrofitMock, only()).getFollowers(null);
+        verify(retrofitMock, only()).getFollowers(null, null);
         assertThat(actual).isEqualTo(response);
     }
 

line-bot-model/src/main/java/com/linecorp/bot/model/request/GetFollowersRequest.java

@@ -57,6 +57,14 @@ public class GetFollowersRequest {
     @Nullable
     String next;
 
+    /**
+     * The maximum number of user IDs to retrieve in a single request.
+     * The default value is 300. If you specify a value that exceeds the maximum, the maximum value will be set.
+     * Max value: 1000
+     */
+    @Nullable
+    Integer limit;
+
     public static GetFollowersRequestBuilder fromResponse(GetFollowersResponse response) {
         return builder().next(response.getNext());
     }