/**
* INTERNAL:
* Initialize a ManyToOneMapping.
*/
protected ManyToOneMapping initManyToOneMapping() {
ManyToOneMapping mapping = new ManyToOneMapping();
processRelationshipMapping(mapping);
mapping.setIsOptional(isOptional());
mapping.setDerivesId(derivesId());
// Process the indirection.
processIndirection(mapping);
// Process a @ReturnInsert and @ReturnUpdate (to log a warning message)