anchor.diff:           get_var_exports/1, get_env_vars/1, get_bound_vars/1, get_free_vars/1, 
            get_client_files/2, expand_files/2, get_modules_by_file/1,
            reset_attrs/1, update_ann/2,parse_annotate_file_1/5, parse_annotate_file/3,
  -         parse_annotate_file/4,write_refactored_files/1, write_refactored_files_for_preview/1,
  +         parse_annotate_file/4,write_refactored_files/1, write_refactored_files_for_preview/2,
            build_lib_side_effect_tab/1, build_local_side_effect_tab/2,
   	 build_scc_callgraph/1,build_callercallee_callgraph/1, has_side_effect/3,
            callback_funs/1,auto_imported_bifs/0, called_funs/2, file_format/1, rewrite/2]).
  
positive.code: 	_ -> throw({error, "Wrangler failed to rewrite the refactored files."})
      end.
  
  write_refactored_files_for_preview(Files) ->
      F = fun(FileAST) ->
  		case FileAST of 
  		    {{FileName,NewFileName}, AST} ->
  
negative.code: 				      end
  			      end, FilePairs),
  		throw({error, "Wrangler failed to output the refactoring result."});
  	_ -> wrangler_preview_server:add_files({FilePairs, LogMsg})
      end.
  
  
  