* Process a map key for a 1-M or M-M mapping. Will return the map key
* method name that should be use, null otherwise.
*/
public String process(CollectionMapping mapping, MappingAccessor mappingAccessor) {
MetadataDescriptor referenceDescriptor = mappingAccessor.getReferenceDescriptor();
MetadataLogger logger = mappingAccessor.getLogger();
if ((! hasName()) && referenceDescriptor.hasCompositePrimaryKey()) {
// No persistent property or field name has been provided, and the
// reference class has a composite primary key class. Return null,
// internally, EclipseLink will use an instance of the composite