Dataspace Use Case #6 - ASCI

User would like to create a two 3-D datasets which share the same dataspace.

Route:

1. User creates a 3-D dataspace.
2. User "commits" dataspace to file, giving it a name. ("DS1")
3. User creates a dataset 'A' with committed 3-D dataspace.
4. User creates second dataset 'B' with committed 3-D dataspace.