    # File lib/prawn/font.rb, line 178
        def font_families
          @font_families ||= Hash.new { |h,k| h[k] = {} }.merge!(
            { "Courier"     => { :bold        => "Courier-Bold",
                                 :italic      => "Courier-Oblique",
                                 :bold_italic => "Courier-BoldOblique",
                                 :normal      => "Courier" },

              "Times-Roman" => { :bold         => "Times-Bold",
                                 :italic       => "Times-Italic",
                                 :bold_italic  => "Times-BoldItalic",
                                 :normal       => "Times-Roman" },

              "Helvetica"   => { :bold         => "Helvetica-Bold",
                                 :italic       => "Helvetica-Oblique",
                                 :bold_italic  => "Helvetica-BoldOblique",
                                 :normal       => "Helvetica" }
            })
        end