Attachable Storage
An abstract placeholder of a onap.capabilities.Storage required by the model from the cloud infrastructure.
Normally, a dangling requirement of type onap.capabilities.Attachment is sufficient to specify an abstraction of Storage resource. The onap.capabilities.AbstractStorage allows the designer to clearly designate sharing of the same attachable storage by multiple components.
TODO: an example of topology where one component node just has a dangling requirement, and two others share an AbstractStorage