text: # Copyright 2013 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  
  from file_system import FileSystem, FileNotFoundError
  
  class OfflineFileSystem(FileSystem):
    '''An offline FileSystem which masquerades as another file system. It throws
    FileNotFound error for all operations, and overrides GetIdentity.
    '''
    def __init__(self, fs):
      self._fs = fs
  
    def Read(self, paths, binary=False):
      raise FileNotFoundError('File system is offline, cannot read %s' % paths)
  
    def Stat(self, path):
      raise FileNotFoundError('File system is offline, cannot read %s' % path)
  
    def GetIdentity(self):
      return self._fs.GetIdentity()
  