def send_assets(from, send_asset_params, fees = nil, mode = 'broadcast')
      transfer_specs = send_asset_params.map{ |param|
        colored_outputs = get_unspent_outputs([oa_address_to_address(param.from || from)])
        [param.asset_id, OpenAssets::Transaction::TransferParameters.new(colored_outputs, param.to, param.from || from, param.amount)]
      }
      btc_transfer_spec = OpenAssets::Transaction::TransferParameters.new(
          get_unspent_outputs([oa_address_to_address(from)]), nil, oa_address_to_address(from), 0)
      tx = create_tx_builder.transfer_assets(transfer_specs, btc_transfer_spec, fees.nil? ? @config[:default_fees]: fees)
      tx = process_transaction(tx, mode)
      tx
    end
def send_assets(from, send_asset_params, fees = nil, mode = 'broadcast')
      transfer_specs = send_asset_params.map{ |param|
        colored_outputs = get_unspent_outputs([oa_address_to_address(param.from || from)])
        [param.asset_id, OpenAssets::Transaction::TransferParameters.new(colored_outputs, param.to, param.from || from, param.amount)]
      }
      btc_transfer_spec = OpenAssets::Transaction::TransferParameters.new(
          get_unspent_outputs([oa_address_to_address(from)]), nil, oa_address_to_address(from), 0)
      tx = create_tx_builder.transfer_assets(transfer_specs, btc_transfer_spec, fees.nil? ? @config[:default_fees]: fees)
      tx = process_transaction(tx, mode)
      tx
    end
Creates a transaction for sending multiple asset from an address to another.
 @param[String] from The open asset address to send the asset from when send_asset_param hasn't from.
 to send the bitcoins from, if needed. where to send bitcoin change, if any.
 @param[Array[OpenAssets::SendAssetParam]] send_asset_params The send Asset information(asset_id, amount, to, from).
 @param[Integer] fees The fess in satoshis for the transaction.
 @param[String] mode 'broadcast' (default) for signing and broadcasting the transaction,
 'signed' for signing the transaction without broadcasting,
 'unsigned' for getting the raw unsigned transaction without broadcasting"""='broadcast'
 @return[Bitcoin::Protocol:Tx] The resulting transaction.