@Override
    public void deleteBlogPost(DeleteBlogPostRequest request, StreamObserver<Empty> responseObserver) {
        final BlogPost removed = blogPosts.remove(request.getId());
        if (removed == null) {
            responseObserver.onError(
                    Status.NOT_FOUND.withDescription("The blog post does not exist. ID: " + request.getId())
                                    .asRuntimeException());
        } else {
            responseObserver.onNext(Empty.getDefaultInstance());
            responseObserver.onCompleted();
        }
    }
Retrieves a {@link BlogPost} whose {@link BlogPost#getId()} is the {@link GetBlogPostRequest#getId()}.
examples/tutorials/grpc/src/main/java/example/armeria/server/blog/grpc/BlogService.java