Upport the "mark invoice as sent" wizard from v8 to v10

PEP8 on account_usability

account_usability/wizard/account_invoice_mark_sent.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+# © 2017 Akretion (Alexis de Lattre <alexis.delattre@akretion.com>)
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from openerp import models
+import logging
+logger = logging.getLogger(__name__)
+
+
+class AccountInvoiceMarkSent(models.TransientModel):
+    _name = 'account.invoice.mark.sent'
+    _description = 'Mark invoices as sent'
+
+    def run(self):
+        assert self.env.context.get('active_model') == 'account.invoice',\
+            'Source model must be invoices'
+        assert self.env.context.get('active_ids'), 'No invoices selected'
+        invoices = self.env['account.invoice'].search([
+            ('id', 'in', self.env.context.get('active_ids')),
+            ('state', 'in', ('open', 'paid'))])
+        invoices.write({'sent': True})
+        logger.info('Marking invoices with ID %s as sent', invoices.ids)
+        return