'Adds a permission to the backend, model permission
:param name:
name of the permission: \'can_add\',\'can_edit\' etc...'

def add_permission(self, name):

    perm = self.find_permission(name)
    if (perm is None):
        try:
            perm = self.permission_model(name=name)
            perm.save()
            return perm
        except Exception as e:
            log.error(c.LOGMSG_ERR_SEC_ADD_PERMISSION.format(str(e)))
    return perm
