This operation returns the data structure associated with a given Management Domain (MD) identified by the provided mdName.
The operation can only be directed to a top-level OS and not to a subordinate OS.

Operation Exceptions: 
1. INTERNAL_ERROR - Raised in case of non-specific OS internal failure. 
2. NOT_IMPLEMENTED - Raised when the OS does not support this operation.
3. INVALID_INPUT - Raised when mdName does not reference an MD object. 
4. ENTITY_NOT_FOUND - Raised when mdName references an MD object that does not exist.
5. COMM_FAILURE - Raised when communication to an entity (needed to help fulfill the request) is lost.
