How to use the pynvim.plugin.decorators.rpc_export function in pynvim

    @rpc_export('python_do_range', sync=True)
    def python_do_range(self, start, stop, code):
        """Handle the `pydo` ex command."""
        self._set_current_range(start, stop)
        nvim = self.nvim
        start -= 1
        fname = '_vim_pydo'

        # define the function
        function_def = 'def %s(line, linenr):\n %s' % (fname, code,)
        exec(function_def, self.module.__dict__)
        # get the function
        function = self.module.__dict__[fname]
        while start < stop:
            # Process batches of 5000 to avoid the overhead of making multiple
            # API calls for every line. Assuming an average line length of 100
            # bytes, approximately 488 kilobytes will be transferred per batch,

    @rpc_export('python_chdir', sync=False)
    def python_chdir(self, cwd):
        """Handle working directory changes."""
        os.chdir(cwd)

    @rpc_export('python_eval', sync=True)
    def python_eval(self, expr):
        """Handle the `pyeval` vim function."""
        return eval(expr, self.module.__dict__)

    @rpc_export('python_execute', sync=True)
    def python_execute(self, script, range_start, range_stop):
        """Handle the `python` ex command."""
        self._set_current_range(range_start, range_stop)
        try:
            exec(script, self.module.__dict__)
        except Exception:
            raise ErrorResponse(format_exc_skip(1))

    @rpc_export('python_execute_file', sync=True)
    def python_execute_file(self, file_path, range_start, range_stop):
        """Handle the `pyfile` ex command."""
        self._set_current_range(range_start, range_stop)
        with open(file_path) as f:
            script = compile(f.read(), file_path, 'exec')
            try:
                exec(script, self.module.__dict__)
            except Exception:
                raise ErrorResponse(format_exc_skip(1))