Create DataONE SystemMetadata objectSource:
A class representing DataONE SystemMetadata, which is core information about objects stored in a repository and needed to manage those objects across systems. SystemMetadata contains basic identification, ownership, access policy, replication policy, and related metadata.
If the *sysmeta* parameter is specified, then construct a new SystemMetadata instance by using the fields from an XML representation of the SystemMetadata.
A value of type
"XMLInternalElementNode", containing the parsed XML element with SystemMetadata fields.