if (sourceField == null) {
throw error(_field, L.l("OneToOne target '{0}' does not have a matching ManyToOne relation.",
targetType.getName()));
}
DependentEntityOneToOneField oneToOne;
oneToOne = new DependentEntityOneToOneField(_sourceType, _fieldName, getCascade());
oneToOne.setTargetField(sourceField);
sourceField.setTargetField(oneToOne);
oneToOne.setLazy(isFetchLazy());
_sourceType.addField(oneToOne);
}