&& extensionSpaceOccupation.checkIntersections(begin, end)) {
&& extensionSpaceOccupation.occupationsIntersection(begin, end)) {
    private void checkExtensionSpaceOccupationIntersection(YearMonthDay begin, YearMonthDay end, Extension extension) {        checkEndDate(begin, end);	for (ExtensionSpaceOccupation extensionSpaceOccupation : extension.getExtensionSpaceOccupations()) {            if (!extensionSpaceOccupation.equals(this)                    && extensionSpaceOccupation.checkIntersections(begin, end)) {                throw new DomainException("error.extensionSpaceOccupation.intersection");            }        }    } 