    # File lib/chef/knife/core/generic_presenter.rb, line 90
            def parse_format_option
              case config[:format]
              when "summary", /^s/, nil
                :summary
              when "text", /^t/
                :text
              when "json", /^j/
                :json
              when "yaml", /^y/
                :yaml
              when "pp", /^p/
                :pp
              else
                raise ArgumentError, "Unknown output format #{config[:format]}"
              end
            end