UMLR — PackageImport Missing for Type Generalization

In the XMI representation of the metamodel for UML 2.5.1:

• The package Classification defines the class InstanceValue.
• InstanceValue contains a generalization to the class ValueSpecification.
• ValueSpecification is defined in the package Values.
• The package Classification does not contain a packageImport element for the Values package or for any other package which itself imports Values. This renders the type of ValueSpecification undefined at the point where it is used by InstanceValue.

The most immediate solution appears to be to add a packageImport to the definition of the Classification package, e.g., '<packageImport xmi:type="uml:PackageImport" xmi:id="Classification-_packageImport.3" importedPackage="Values"/>'.