':class:`~odoo.sql_db.Cursor` initialized for the current method call.
Accessing the cursor when the current request uses the ``none``
authentication will raise an exception.'

@property
def cr(self):

    if (not self.db):
        raise RuntimeError('request    not    bound    to    a    database')
    if (not self._cr):
        self._cr = self.registry.cursor()
    return self._cr
