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: token_stream.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/rdoc-4.3.0/lib/rdoc
    
    the code of the file until where you have to start completion: ##
# A TokenStream is a list of tokens, gathered during the parse of some entity
# (say a method). Entities populate these streams by being registered with the
# lexer. Any class can collect tokens by including TokenStream. From the
# ou
    
  def self.to_html token_stream
    token_stream.map do |t|
      next unless t

      style = case t
              when RDoc::RubyToken::TkCONSTANT then 'ruby-constant'
              when RDoc::RubyToken::TkKW       then 'ruby-keyword'
              when RDoc::RubyToken::TkIVAR     then 'ruby-ivar'
              when RDoc::RubyToken::TkOp       then 'ruby-operator'
              when RDoc::RubyToken::TkId       then 'ruby-identifier'
              when RDoc::RubyToken::TkNode     then 'ruby-node'
              when RDoc::RubyToken::TkCOMMENT  then 'ruby-comment'
              when RDoc::RubyToken::TkREGEXP   then 'ruby-regexp'
              when RDoc::RubyToken::TkSTRING   then 'ruby-string'
              when RDoc::RubyToken::TkVal      then 'ruby-value'
              end

      text = CGI.escapeHTML t.text

      if style then
        "<span class=\"#{style}\">#{text}</span>"
      else
        text
      end