How to use the vulture.utils.format_path function in vulture

def scan(self, code, filename=''):
        code = utils.sanitize_code(code)
        self.code = code.splitlines()
        self.filename = filename
        try:
            node = ast.parse(code, filename=self.filename)
        except SyntaxError as err:
            text = ' at "{}"'.format(err.text.strip()) if err.text else ''
            print('{}:{:d}: {}{}'.format(
                utils.format_path(filename), err.lineno, err.msg, text),
                file=sys.stderr)
            self.found_dead_code_or_error = True
        except (TypeError, ValueError) as err:
            # Python < 3.5 raises TypeError and Python >= 3.5 raises
            # ValueError if source contains null bytes.
            print('{}: invalid source code "{}"'.format(
                utils.format_path(filename), err), file=sys.stderr)
            self.found_dead_code_or_error = True
        else:
            self.visit(node)

code = utils.sanitize_code(code)
        self.code = code.splitlines()
        self.filename = filename
        try:
            node = ast.parse(code, filename=self.filename)
        except SyntaxError as err:
            text = ' at "{}"'.format(err.text.strip()) if err.text else ''
            print('{}:{:d}: {}{}'.format(
                utils.format_path(filename), err.lineno, err.msg, text),
                file=sys.stderr)
            self.found_dead_code_or_error = True
        except (TypeError, ValueError) as err:
            # Python < 3.5 raises TypeError and Python >= 3.5 raises
            # ValueError if source contains null bytes.
            print('{}: invalid source code "{}"'.format(
                utils.format_path(filename), err), file=sys.stderr)
            self.found_dead_code_or_error = True
        else:
            self.visit(node)

def get_report(self, add_size=False):
        if add_size:
            line_format = 'line' if self.size == 1 else 'lines'
            size_report = ', {:d} {}'.format(self.size, line_format)
        else:
            size_report = ''
        return "{}:{:d}: {} ({}% confidence{})".format(
            utils.format_path(self.filename), self.first_lineno,
            self.message, self.confidence, size_report)

def get_whitelist_string(self):
        filename = utils.format_path(self.filename)
        if self.typ == 'unreachable_code':
            return ('# {} ({}:{})'.format(
                self.message, filename, self.first_lineno))
        else:
            prefix = '_.' if self.typ in ['attribute', 'property'] else ''
            return "{}{}  # unused {} ({}:{:d})".format(
                    prefix, self.name, self.typ, filename, self.first_lineno)