anchor.diff:  
   make_match_expr(Expr, NewVarName) ->
       Pat = refac_syntax:variable(NewVarName),
  -    refac_syntax:match_expr(Pat, Expr).
  -
  -get_inmost_enclosing_clause(Form, Expr) ->
  +    PreComs = refac_syntax:get_precomments(Expr),
  +    PostComs=refac_syntax:get_postcomments(Expr),
  +    Expr1=refac_syntax:set_precomments(refac_syntax:set_postcomments(Expr, []),[]),
  +    MatchExpr=refac_syntax:match_expr(Pat, Expr1),
  +    refac_syntax:set_precomments(refac_syntax:set_postcomments(MatchExpr, PostComs), PreComs).
  +
  +get_inmost_enclosing_clause(Form, Expr) -> 
       ExprPos = refac_syntax:get_pos(Expr),
       Fun = fun (Node, S) ->
   		  Type = refac_syntax:type(Node),
  
positive.code: 	    throw({error, "The new variable name conflicts with, or shadows, "
  			  "existing variable declarations."});
  	false -> ok
      end.
  
  get_bound_vars(Tree) ->
  
negative.code: 	    refac_util:rewrite(Node,refac_syntax:try_expr(NewBody, C, H, A))
      end.
  
  
  replace_expr_with_var(Expr, NewVarName, ExprStatement) ->
      ast_traverse_api:stop_tdTP(fun do_replace_expr_with_var/2,
  			       ExprStatement, {Expr, NewVarName}).
  