You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: params.rb
    path of file: ./repos/ferrocarril/mruby-gems/vendor/ruby/2.6.0/gems/rack-2.0.7/lib/rack/auth/digest
    
    the code of the file until where you have to start completion: module Rack
  module Auth
    module Digest
      class Params < Hash

        def self.parse(str)
          Params[*split_header_value(str).map do |param|
            k, v = param.split('=', 2)
            [k, dequote(v)]
          end.flatten]
        end

        def self.dequote(str) # From WEBrick::HTTPUtils
          ret = (/\A"(.*)"\Z/ =~ str) ? $1 : str.dup
          ret.gsub!(/\\(.)/, "\\1")
          ret
        end

        def self.split_header_value(str)
          str.scan(/\w+\=(?:"[^\"]+"|[^,]+)/n)
        end

        def initialize
          super()

          yield self if block_giv
    
        def self.parse(str)
          Params[*split_header_value(str).map do |param|
            k, v = param.split('=', 2)
            [k, dequote(v)]
          end.flatten]
        end

        def self.dequote(str) # From WEBrick::HTTPUtils
          ret = (/\A"(.*)"\Z/ =~ str) ? $1 : str.dup
          ret.gsub!(/\\(.)/, "\\1")
          ret
        end

        def self.split_header_value(str)
          str.scan(/\w+\=(?:"[^\"]+"|[^,]+)/n)
        end

        def initialize
          super()

          yield self if block_given?
        end

        def [](k)
          super k.to_s
        end

        def []=(k, v)
          super k.to_s, v.to_s
        end

        UNQUOTED = ['nc', 'stale']

        def to_s
          map do |k, v|
            "#{k}=" << (UNQUOTED.include?(k) ? v.to_s : quote(v))
          end.join(', ')
        end

        def quote(str) # From WEBrick::HTTPUtils
          '"' << str.gsub(/[\\\"]/o, "\\\1") << '"'
        end

      end
    end