Add public note.

        :param public_note: public note for the current article.
        :type public_note: string

        :param source: source for the given notes.
        :type source: string

def add_public_note(self, public_note, source=None):
        """Add public note.

        :param public_note: public note for the current article.
        :type public_note: string

        :param source: source for the given notes.
        :type source: string
        """
        self._append_to('public_notes', self._sourced_dict(
            source,
            value=public_note,
        ))