See the Javadocs in <EPM_ORACLE_HOME>/common/docs/ReportingAnalysis/SDK/javadoc.
This interface defines additional methods that can be invoked on artifacts that are stored in EPM Workspace, such as HTML documents, Production Reporting documents, and comma-separated value (CSV) data files. The interface enables your program to obtain keyword lists associated with the artifact, to update the DataObject content, and to retrieve contents from the local file system.