There is no documentation for error handling

[amir14a]

Hi, static functions editImage, editFileImage and editFileImageAndGetFile return type is nullable, (meanwhile editImageAndGetFile is non-nullable!!!!)

And this is a comment in this functions:
/// If result is null, it means handle image error.

But,

• How to handle error?? there is no documentation for that.
• If function can throw an exception, why the return type is nullable?
• By reading the source code, I realize that it can throw a HandleError object. Why you choose this name? Isn't it better to be something like ImageEditorError