code: def FVDEVolumeOpen(fvde_volume, path_spec, file_object, key_chain):
    
    encrypted_root_plist = key_chain.GetCredential(
        path_spec, 'encrypted_root_plist')
    if encrypted_root_plist:
      fvde_volume.read_encrypted_root_plist(encrypted_root_plist)
  
    password = key_chain.GetCredential(path_spec, 'password')
    if password:
      fvde_volume.set_password(password)
  
    recovery_password = key_chain.GetCredential(path_spec, 'recovery_password')
    if recovery_password:
      fvde_volume.set_recovery_password(recovery_password)
  
    fvde_volume.open_file_object(file_object)
docs: Opens the FVDE volume using the path specification.
  
    Args:
      fvde_volume (pyfvde.volume): FVDE volume.
      path_spec (PathSpec): path specification.
      file_object (FileIO): file-like object.
      key_chain (KeyChain): key chain.