Fix malformed note directives.

        submission to the server.

    .. note::

        On occasions it may be useful to require or restrict the keys which are

        valid for a given field. This can be done using the

        :class:`~django.contrib.postgres.validators.KeysValidator`.

  ``__init__`` method. Every value should itself be serializable.

.. note::

    This return value is different from the ``deconstruct()`` method

    :ref:`for custom fields <custom-field-deconstruct-method>` which returns a

    tuple of four items.