How to use the xlwings.xlplatform.get_xl_workbook_current function in xlwings

self.col2 = args[1][1]
        elif len(args) == 3:
            if isinstance(args[0], Sheet):
                sheet_name_or_index = args[0].index
            else:
                sheet_name_or_index = args[0]
            range_address = None
            self.row1 = args[1][0]
            self.col1 = args[1][1]
            self.row2 = args[2][0]
            self.col2 = args[2][1]

        # Keyword Arguments
        self.kwargs = kwargs
        self.workbook = kwargs.get('wkb', None)
        if self.workbook is None and xlplatform.get_xl_workbook_current() is None:
            raise NameError('You must first instantiate a Workbook object.')
        elif self.workbook is None:
            self.xl_workbook = xlplatform.get_xl_workbook_current()
        else:
            self.xl_workbook = self.workbook.xl_workbook
        self.index = kwargs.get('index', True)  # Set DataFrame with index
        self.header = kwargs.get('header', True)  # Set DataFrame with header
        self.asarray = kwargs.get('asarray', False)  # Return Data as NumPy Array
        self.strict = kwargs.get('strict', False)  # Stop table/horizontal/vertical at empty cells that contain formulas
        self.atleast_2d = kwargs.get('atleast_2d', False)  # Force data to be list of list or a 2d numpy array

        # Get sheet
        if sheet_name_or_index:
            self.xl_sheet = xlplatform.get_worksheet(self.xl_workbook, sheet_name_or_index)
        else:
            self.xl_sheet = xlplatform.get_active_sheet(self.xl_workbook)

.. versionadded:: 0.3.0
        """
        if hasattr(Workbook, '_mock_file'):
            # Use mocking Workbook, see Workbook.set_mock_caller()
            _, xl_workbook = xlplatform.get_open_workbook(Workbook._mock_file)
            return cls(xl_workbook=xl_workbook)
        elif len(sys.argv) > 2 and sys.argv[2] == 'from_xl':
            # Connect to the workbook from which this code has been invoked
            fullname = sys.argv[1].lower()
            if sys.platform.startswith('win'):
                xl_app, xl_workbook = xlplatform.get_open_workbook(fullname, hwnd=sys.argv[4])
                return cls(xl_workbook=xl_workbook)
            else:
                xl_app, xl_workbook = xlplatform.get_open_workbook(fullname, app_target=sys.argv[3])
                return cls(xl_workbook=xl_workbook, app_target=sys.argv[3])
        elif xlplatform.get_xl_workbook_current():
            # Called through ExcelPython connection
            return cls(xl_workbook=xlplatform.get_xl_workbook_current())
        else:
            raise Exception('Workbook.caller() must not be called directly. Call through Excel or set a mock caller '
                            'first with Workbook.set_mock_caller().')

def get_xl_workbook(wkb):
        """
        Returns the ``xl_workbook_current`` if ``wkb`` is ``None``, otherwise the ``xl_workbook`` of ``wkb``. On Windows,
        ``xl_workbook`` is a pywin32 COM object, on Mac it's an appscript object.

        Arguments
        ---------
        wkb : Workbook or None
            Workbook object
        """
        if wkb is None and xlplatform.get_xl_workbook_current() is None:
            raise NameError('You must first instantiate a Workbook object.')
        elif wkb is None:
            xl_workbook = xlplatform.get_xl_workbook_current()
        else:
            xl_workbook = wkb.xl_workbook
        return xl_workbook

def get_xl_workbook(wkb):
        """
        Returns the ``xl_workbook_current`` if ``wkb`` is ``None``, otherwise the ``xl_workbook`` of ``wkb``. On Windows,
        ``xl_workbook`` is a pywin32 COM object, on Mac it's an appscript object.

        Arguments
        ---------
        wkb : Workbook or None
            Workbook object
        """
        if wkb is None and xlplatform.get_xl_workbook_current() is None:
            raise NameError('You must first instantiate a Workbook object.')
        elif wkb is None:
            xl_workbook = xlplatform.get_xl_workbook_current()
        else:
            xl_workbook = wkb.xl_workbook
        return xl_workbook

def current(cls):
        """
        Returns the current Workbook object, i.e. the default Workbook used by ``Sheet``, ``Range`` and ``Chart`` if not
        specified otherwise. On Windows, in case there are various instances of Excel running, opening an existing or
        creating a new Workbook through ``Workbook()`` is acting on the same instance of Excel as this Workbook. Use
        like this: ``Workbook.current()``.

        .. versionadded:: 0.2.2
        """
        return cls(xl_workbook=xlplatform.get_xl_workbook_current(), app_visible=None)

sheet_name_or_index = args[0].index
            else:
                sheet_name_or_index = args[0]
            range_address = None
            self.row1 = args[1][0]
            self.col1 = args[1][1]
            self.row2 = args[2][0]
            self.col2 = args[2][1]

        # Keyword Arguments
        self.kwargs = kwargs
        self.workbook = kwargs.get('wkb', None)
        if self.workbook is None and xlplatform.get_xl_workbook_current() is None:
            raise NameError('You must first instantiate a Workbook object.')
        elif self.workbook is None:
            self.xl_workbook = xlplatform.get_xl_workbook_current()
        else:
            self.xl_workbook = self.workbook.xl_workbook
        self.index = kwargs.get('index', True)  # Set DataFrame with index
        self.header = kwargs.get('header', True)  # Set DataFrame with header
        self.asarray = kwargs.get('asarray', False)  # Return Data as NumPy Array
        self.strict = kwargs.get('strict', False)  # Stop table/horizontal/vertical at empty cells that contain formulas
        self.atleast_2d = kwargs.get('atleast_2d', False)  # Force data to be list of list or a 2d numpy array

        # Get sheet
        if sheet_name_or_index:
            self.xl_sheet = xlplatform.get_worksheet(self.xl_workbook, sheet_name_or_index)
        else:
            self.xl_sheet = xlplatform.get_active_sheet(self.xl_workbook)

        # Get xl_range object
        if range_address:

if hasattr(Workbook, '_mock_file'):
            # Use mocking Workbook, see Workbook.set_mock_caller()
            _, xl_workbook = xlplatform.get_open_workbook(Workbook._mock_file)
            return cls(xl_workbook=xl_workbook)
        elif len(sys.argv) > 2 and sys.argv[2] == 'from_xl':
            # Connect to the workbook from which this code has been invoked
            fullname = sys.argv[1].lower()
            if sys.platform.startswith('win'):
                xl_app, xl_workbook = xlplatform.get_open_workbook(fullname, hwnd=sys.argv[4])
                return cls(xl_workbook=xl_workbook)
            else:
                xl_app, xl_workbook = xlplatform.get_open_workbook(fullname, app_target=sys.argv[3])
                return cls(xl_workbook=xl_workbook, app_target=sys.argv[3])
        elif xlplatform.get_xl_workbook_current():
            # Called through ExcelPython connection
            return cls(xl_workbook=xlplatform.get_xl_workbook_current())
        else:
            raise Exception('Workbook.caller() must not be called directly. Call through Excel or set a mock caller '
                            'first with Workbook.set_mock_caller().')