# File lib/prawn/graph/themes.rb, line 29
      def self._register_theme(theme_file_path)
        theme = Theme.new(YAML.load(IO.read(File.expand_path(theme_file_path))))
        if !defined? @@_themes_list
          @@_themes_list = {}
        end
        @@_themes_list[theme.name.to_sym] = theme
      end