Importing batch sometimes exceed reference column length limit

It is possible to create an importer with a batch reference that will cause an error because of the generated reference exceeds the column length in the database. For someone creating an importer plugin this is difficult to expect that the code doesn't check the length. This is an example of error in the log :

[debug] $backTrace = #0 /srv/www/d7-master/web/sites/all/modules/civicrm/CRM/Core/Error.php(236): CRM_Core_Error::backtrace("backTrace", TRUE)
#1 /srv/www/d7-master/web/sites/all/modules/civicrm/vendor/pear/pear-core-minimal/src/PEAR.php(922): CRM_Core_Error::handle(Object(DB_Error))
#2 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB.php(987): PEAR_Error->__construct("DB Error: unknown error", -1, 16, (Array:2), "UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...")
#3 /srv/www/d7-master/web/sites/all/modules/civicrm/vendor/pear/pear-core-minimal/src/PEAR.php(575): DB_Error->__construct(-1, 16, (Array:2), "UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...")
#4 /srv/www/d7-master/web/sites/all/modules/civicrm/vendor/pear/pear-core-minimal/src/PEAR.php(223): PEAR->_raiseError(Object(DB_mysqli), NULL, -1, 16, (Array:2), "UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...", "DB_Error", TRUE)
#5 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/common.php(1920): PEAR->__call("raiseError", (Array:7))
#6 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/mysqli.php(933): DB_common->raiseError(-1, NULL, NULL, "UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...", "1406 ** Data too long for column 'reference' at row 1")
#7 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/mysqli.php(403): DB_mysqli->mysqliRaiseError()
#8 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/common.php(1229): DB_mysqli->simpleQuery("UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...")
#9 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/DataObject.php(2416): DB_common->query("UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...")
#10 /srv/www/d7-master/web/sites/all/modules/civicrm/packages/DB/DataObject.php(1318): DB_DataObject->_query("UPDATE  civicrm_bank_tx_batch  SET issue_date = 20191022115829 , reference = ...")
#11 /srv/www/d7-master/web/sites/all/modules/civicrm/CRM/Core/DAO.php(560): DB_DataObject->update()
#12 /srv/www/d7-master/web/sites/default/files/civicrm/ext/org.project60.banking/extension/CRM/Banking/PluginModel/Importer.php(282): CRM_Core_DAO->save()
#13 /srv/www/d7-master/web/sites/default/files/civicrm/ext/org.project60.banking/extension/CRM/Banking/PluginImpl/Importer/CSV.php(190): CRM_Banking_PluginModel_Importer->closeTransactionBatch(TRUE)
#14 /srv/www/d7-master/web/sites/default/files/civicrm/ext/org.project60.banking/extension/CRM/Banking/Page/Import.php(58): CRM_Banking_PluginImpl_Importer_CSV->import_file("/tmp/phpUbjg4e", (Array:2))
#15 /srv/www/d7-master/web/sites/all/modules/civicrm/CRM/Core/Invoke.php(284): CRM_Banking_Page_Import->run((Array:3), NULL)
#16 /srv/www/d7-master/web/sites/all/modules/civicrm/CRM/Core/Invoke.php(84): CRM_Core_Invoke::runItem((Array:13))
#17 /srv/www/d7-master/web/sites/all/modules/civicrm/CRM/Core/Invoke.php(52): CRM_Core_Invoke::_invoke((Array:3))
#18 /srv/www/d7-master/web/sites/all/modules/civicrm/drupal/civicrm.module(444): CRM_Core_Invoke::invoke((Array:3))
#19 /srv/www/d7-master/web/includes/menu.inc(527): civicrm_invoke("banking", "import")
#20 /srv/www/d7-master/web/index.php(21): menu_execute_active_handler()
#21 {main}

Start in sites/default/files/civicrm/ext/org.project60.banking/extension/CRM/Banking/PluginModel/Importer.php around line 282, where closeTransactionBatch saves the batch. Trace how the generated reference is assembled and how its database length is known; done means an oversized reference no longer causes the import to fail with a data-too-long error.