Request:
{"method":"model.sale.line-account.tax","params":[5,"9787dab66789htba215a0651a7fff2a",[[]],0,null,[[]],[],{}]}

Response:

{
  "id": 0,
  "error": [
    "u'sale.line-account'",
    "Traceback (most recent call last):\n  File \"/trytond/protocols/wsgi/__init__.py\", line 55, in jsonrpc_app\n    response['result'] = dispatch(*args)\n  File \"/trytond/protocols/dispatcher.py\", line 140, in dispatch\n    obj = pool.get(object_name, type=object_type)\n  File \"/trytond/pool.py\", line 168, in get\n    return self._pool[self.database_name][type][name]\nKeyError: u'sale.line-account'\n"
  ]
}