private List <KeyValuePair <Contact, string> > GenerateTemplates(List <Contact> contacts)
        {
            var contactsDocuments = new List <KeyValuePair <Contact, string> >();

            foreach (var contact in contacts)
            {
                var newContact = _inventoryManager.AddSerialNumber(contact);
                contactsDocuments.Add(new KeyValuePair <Contact, string>(newContact, GetDocumentForContact(newContact)));
                _logger.Information(
                    $"Template successfuly generated for {newContact.Name} / {newContact.Mail} / {newContact.SerialNumber}");
            }

            return(contactsDocuments);
        }