title: Model Derivative API: What is the scope of a bucket?
body: <p>Can you please give a bit more information about the scope of a bucket? I experienced a situation that I started with searching for a bucket, and I did not find it into my actual list of bucket keys. 
  Ok, but trying to create a new bucket with that key, I received the error that this was not possible because it was already a bucket with that key. {"reason":"Bucket already exists"}</p>