code: def PrepareMatches(self, file_system):
      
      if self._location is not None:
        self._location_segments = self._SplitPath(
            self._location, file_system.PATH_SEPARATOR)
  
      elif self._location_regex is not None:
        path_separator = file_system.PATH_SEPARATOR
        if path_separator == '\\':
          # The backslash '\' is escaped within a regular expression.
          path_separator = '\\\\'
  
        self._location_segments = self._SplitPath(
            self._location_regex, path_separator)
  
      if self._location_segments is not None:
        self._number_of_location_segments = len(self._location_segments)
docs: Prepare find specification for matching.
  
      Args:
        file_system (FileSystem): file system.