break;
case PSEUDO:
if (specifier instanceof PseudoClassSpecifier) {
checker = new PseudoClassSpecifierChecker((PseudoClassSpecifier) specifier);
} else if (specifier instanceof PseudoNthSpecifier) {
checker = new PseudoNthSpecifierChecker((PseudoNthSpecifier) specifier);
}
break;
case NEGATION:
final Set<Node> negationNodes = checkNegationSpecifier((NegationSpecifier) specifier);