anchor.diff:    }
   
     visitCatchClause(CatchClause node) {
  -
       token(node.onKeyword, followedBy: space);
       visit(node.exceptionType);
   
  
positive.code: 
    visitBlockFunctionBody(BlockFunctionBody node) {
      // The "async" or "sync" keyword.
      if (node.keyword != null) {
        token(node.keyword);
        space();
      }
  
      visit(node.block);
    }
  
negative.code: 
    visitExpressionFunctionBody(ExpressionFunctionBody node) {
      // The "async" or "sync" keyword.
      token(node.keyword, followedBy: space);
  
      int weight = lastSpaceWeight++;
      token(node.functionDefinition);
  