private void processPrologNode(PsiBuilder psiBuilder,
                                 XmlBuilder builder,
                                 FlyweightCapableTreeStructure<LighterASTNode> structure,
                                 LighterASTNode prolog) {
    final Ref<LighterASTNode[]> prologChildren = new Ref<>(null);
    final int prologChildrenCount = structure.getChildren(prolog, prologChildren);
    for (int i = 0; i < prologChildrenCount; i++) {
      LighterASTNode node = prologChildren.get()[i];
      IElementType type = node.getTokenType();
      if (type == XmlElementType.XML_DOCTYPE) {
        processDoctypeNode(builder, structure, node);
        break;
      }
      if (type == TokenType.ERROR_ELEMENT) {
        processErrorNode(psiBuilder, node, builder);
      }
    }
  }
private void processPrologNode(PsiBuilder psiBuilder,
                                 XmlBuilder builder,
                                 FlyweightCapableTreeStructure<LighterASTNode> structure,
                                 LighterASTNode prolog)