private VirtualFile createVirtualFileForRevision(VcsFileRevision revision) {
    if (!myRevisionToVirtualFile.containsKey(revision)) {
      FilePath filePath = (revision instanceof VcsFileRevisionEx ? ((VcsFileRevisionEx)revision).getPath() : myFilePath);
      myRevisionToVirtualFile.put(revision, filePath.isDirectory()
                                            ? new VcsVirtualFolder(filePath.getPath(), null, VcsFileSystem.getInstance())
                                            : new VcsVirtualFile(filePath.getPath(), revision, VcsFileSystem.getInstance()));
    }
    return myRevisionToVirtualFile.get(revision);
  }
private VirtualFile createVirtualFileForRevision(VcsFileRevision revision)