         ).then (required_public_keys)->
             #DEBUG console.log('... get_required_signatures',required_public_keys)
             required_public_keys
-    
+
     add_signer:(private_key, public_key)->
         throw new Error "already signed" if @signed
         unless public_key.Q
             public_key = PublicKey.fromPublicKeyString public_key
         @signer_private_keys.push [private_key, public_key]
-    
+
     sign:(chain_id = Apis.instance().chain_id)->
         throw new Error "not finalized" unless @tr_buffer
         throw new Error "already signed" if @signed

                    @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
