def add_author(self, author, file_as=None, role=None, uid='creator'):
        "Add author for this document"

        self.add_metadata('DC', 'creator', author, {'id': uid})

        if file_as:
            self.add_metadata(None, 'meta', file_as, {'refines': '#' + uid,
                                                      'property': 'file-as',
                                                      'scheme': 'marc:relators'})
        if role:
            self.add_metadata(None, 'meta', role, {'refines': '#' + uid,
                                                   'property': 'role',
                                                   'scheme': 'marc:relators'})
Add author for this document