Blob.update() misses BlobInfo argument

[dmitry-fa]

The Blob class declares method: public Blob update(BlobTargetOption... options)
This method is useless, it doesn't have the necessary BlobInfo parameter.
Documentation to this method mentions Storage.update(), not Blob.update().

This method should be declared as Deprecated (and deleted as soon possible)

A new method with BlobInfo parameter should be added.

[frankyn]

I don't agree we should deprecate this method. Closing this issue for now as I'd prefer organizing a deprecation because users may depend on this method.

An alternative would be to update documentation on how to use this method instead.

Here's an example of how to update metadata for Blob. A similar flow works with Bucket.update() as well.

    Bucket remoteBucket = storage.get("bucket-name");
    Blob remoteBlob = remoteBucket.get("test");
    remoteBlob.toBuilder().setContentType("text/plain").build().update();

[dmitry-fa]

Hi @frankyn, thanks for that example. Yes, I agree, it's not necessary to deprecate this method.
I submitted #252 to fix the spec.