public RuleBuilder withinPair(IElementType pairFirst, IElementType pairSecond) {
    RuleCondition before = new RuleCondition(null, TokenSet.create(pairFirst), null);
    RuleCondition after = new RuleCondition(null, null, TokenSet.create(pairSecond));
    return new RuleBuilder(before, after);
  }
public RuleBuilder withinPair(IElementType pairFirst, IElementType pairSecond)