update the FeatureModel: leaf can be a full mixset/file or a/some fragment of a mixset
update the FeatureModel: leaf can be a full mixset/file or a/some fragment of a mixset

umple/umple,umple/umple,umple/umple,umple/umple,umple/umple,umple/umple,umple/umple,umple/umple