- var request and var response in Init() → const (never reassigned,
var is function-scoped and hoisted which is undesirable in class methods)
- let formData in UploadChunk() → const (never reassigned)
- chunkResponse in UploadChunk() removed (assigned but never read)
- let start in GetChunks() → const (never reassigned)
- var percent in UpdateProgressBar() → const (never reassigned)