                     @tr_buffer = type.transaction.toBuffer @
                     return
             return
-    
+
     get_potential_signatures:()->
         tr_object = type.signed_transaction.toObject @
         Promise.all([

                set_fee @operations[i][1]
            #DEBUG console.log('... get_required_fees',operations,asset_id,flat_assets)
            return
    
    finalize:()->
        new Promise (resolve, reject)=>
            throw new Error "already finalized" if @tr_buffer

                else
                    flat_assets.push obj
                return
            flatten fees
            asset_index = 0
            for i in [0...@operations.length] by 1
                set_fee = (operation) ->
