Return the value of a given field. The list of all queryable fields is
        detailed below, and can be obtained with the
        :py:func:`~TopicModel._list_fields` method.

        +-----------------------+----------------------------------------------+
        |      Field            | Description                                  |
        +=======================+==============================================+
        | topics                | An SFrame containing a column with the unique|
        |                       | words observed during training, and a column |
        |                       | of arrays containing the probability values  |
        |                       | for each word given each of the topics.      |
        +-----------------------+----------------------------------------------+
        | vocabulary            | An SArray containing the words used. This is |
        |                       | same as the vocabulary column in the topics  |
        |                       | field above.                                 |
        +-----------------------+----------------------------------------------+

        Parameters
        ----------
        field : string
            Name of the field to be retrieved.

        Returns
        -------
        out
            Value of the requested field.

def _get(self, field):
        """
        Return the value of a given field. The list of all queryable fields is
        detailed below, and can be obtained with the
        :py:func:`~TopicModel._list_fields` method.

        +-----------------------+----------------------------------------------+
        |      Field            | Description                                  |
        +=======================+==============================================+
        | topics                | An SFrame containing a column with the unique|
        |                       | words observed during training, and a column |
        |                       | of arrays containing the probability values  |
        |                       | for each word given each of the topics.      |
        +-----------------------+----------------------------------------------+
        | vocabulary            | An SArray containing the words used. This is |
        |                       | same as the vocabulary column in the topics  |
        |                       | field above.                                 |
        +-----------------------+----------------------------------------------+

        Parameters
        ----------
        field : string
            Name of the field to be retrieved.

        Returns
        -------
        out
            Value of the requested field.
        """

        opts = {'model': self.__proxy__, 'field': field}
        response = _turicreate.extensions._text.topicmodel_get_value(opts)
        return response['value']