Currently, there are two ways to indicate that the root container should be used in the blob APIs:
// Explicitly indicate root:
// Implicitly indicate, using an empty string:
It seems natural that null could also be used to indicate the root container (even more natural than an empty string), because null means "no container". That would allow code like this to work:
One potential downside would make it harder to debug issues where the container name is not initialized.