How to use the tableaudocumentapi.xfile.xml_open function in tableaudocumentapi

def from_file(cls, filename):
        """Initialize datasource from file (.tds ot .tdsx)"""

        dsxml = xml_open(filename, 'datasource').getroot()
        return cls(dsxml, filename)

def __init__(self, filename):
        """Open the workbook at `filename`. This will handle packaged and unpacked
        workbook files automatically. This will also parse Data Sources and Worksheets
        for access.

        """

        self._filename = filename

        self._workbookTree = xml_open(self._filename, 'workbook')

        self._workbookRoot = self._workbookTree.getroot()
        # prepare our datasource objects
        self._datasources = self._prepare_datasources(
            self._workbookRoot)  # self.workbookRoot.find('datasources')

        self._datasource_index = self._prepare_datasource_index(self._datasources)

        self._worksheets = self._prepare_worksheets(
            self._workbookRoot, self._datasource_index
        )