How to use the importlab.utils function in importlab

def test_strip_suffix(self):
        a = 'foo bar bar'
        self.assertEqual(a, utils.strip_suffix(a, 'hello'))
        self.assertEqual('foo bar ', utils.strip_suffix(a, 'bar'))
        self.assertEqual(a, utils.strip_suffix(a, 'hbar'))

def test_strip_suffix(self):
        a = 'foo bar bar'
        self.assertEqual(a, utils.strip_suffix(a, 'hello'))
        self.assertEqual('foo bar ', utils.strip_suffix(a, 'bar'))
        self.assertEqual(a, utils.strip_suffix(a, 'hbar'))

self.env = env
      cfg = env.config
      self.pythonpath = self.env.pythonpath.split(':')
      self.output_dir = cfg.output_dir
      self.deps = cfg.deps
      self.projects = cfg.projects
      self.system_env = {
          b'TYPESHED_HOME': env.typeshed_location.encode('utf-8')
      }
      self.pyi_dir = os.path.join(self.output_dir, 'pyi')
      try:
          os.makedirs(self.output_dir)
      except:
          pass
      self.log_file = os.path.join(self.output_dir, 'pytype.log')
      self.logger = utils.setup_logging('pytype', self.log_file)

def path_from_pythonpath(pythonpath):
    """Create an fs.Path object from a pythonpath string."""
    path = fs.Path()
    for p in pythonpath.split(os.pathsep):
        path.add_path(utils.expand_path(p), 'os')
    return path

def get_imports(filename, python_version):
    if python_version == sys.version_info[0:2]:
        # Invoke import_finder directly
        try:
            imports = import_finder.get_imports(filename)
        except Exception:
            raise ParseError(filename)
    else:
        # Call the appropriate python version in a subprocess
        f = sys.modules['importlab.import_finder'].__file__
        if f.rsplit('.', 1)[-1] == 'pyc':
            # In host Python 2, importlab ships with .pyc files.
            f = f[:-1]
        ret, stdout, stderr = utils.run_py_file(python_version, f, filename)
        if not ret:
            if sys.version_info[0] == 3:
                stdout = stdout.decode('ascii')
            imports = import_finder.read_imports(stdout)
        else:
            if sys.version_info[0] == 3:
                stderr = stderr.decode('ascii')
            logging.info(stderr)
            raise ParseError(filename)
    return [ImportStatement(*imp) for imp in imports]

# Relative import in non-package
                        raise ImportException(name)
                    module_name = get_absolute_name(package_name, module_name)
                    if isinstance(self.current_module, System):
                        return System(f, module_name)
                return Local(f, module_name, fs)

        # If the module isn't found in the explicit pythonpath, see if python
        # itself resolved it.
        if item.source:
            prefix, ext = os.path.splitext(item.source)
            mod_name = name
            # We need to check for importing a symbol here too.
            if short_name:
                mod = prefix.replace(os.path.sep, '.')
                mod = utils.strip_suffix(mod, '.__init__')
                if not mod.endswith(name) and mod.endswith(short_name):
                    mod_name = short_name

            if ext == '.pyc':
                pyfile = prefix + '.py'
                if os.path.exists(pyfile):
                    return System(pyfile, mod_name)
            elif not ext:
                pyfile = os.path.join(prefix, "__init__.py")
                if os.path.exists(pyfile):
                    return System(pyfile, mod_name)
            return System(item.source, mod_name)

        raise ImportException(name)