docs: private static String exceptionToString(TryTree tree, VisitorState state) {
      if (tree.getCatches().size() != 1) {
        return "Exception";
      }
      Tree exceptionType = tree.getCatches().iterator().next().getParameter().getType();
      Type type = ASTHelpers.getType(exceptionType);
      if (type != null && type.isUnion()) {
        return "Exception";
      }
      return state.getSourceForNode(exceptionType);
    }