protected @Nullable Indent getChildDefaultIndent() {
    if (myNode.getElementType() == XmlElementType.HTML_DOCUMENT) {
      return Indent.getNoneIndent();
    }
    if (myNode.getElementType() == TokenType.DUMMY_HOLDER) {
      return Indent.getNoneIndent();
    }
    if (myNode.getElementType() == XmlElementType.XML_PROLOG) {
      return Indent.getNoneIndent();
    }
    else {
      return null;
    }
  }
protected @Nullable Indent getChildDefaultIndent()