code: def GetFilename(self):
      
      if not self._file_entry:
        return None
  
      data_stream = getattr(self._file_entry.path_spec, 'data_stream', None)
      if data_stream:
        return '{0:s}:{1:s}'.format(self._file_entry.name, data_stream)
  
      return self._file_entry.name
docs: Retrieves the name of the active file entry.
  
      Returns:
        str: name of the active file entry or None.