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: logger.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack
    
    the code of the file until where you have to start completion: require 'logger'

module Rack
  # Sets up rack.logger to write to rack.errors stream
  class
    
    def call(env)
      logger = ::Logger.new(env[RACK_ERRORS])
      logger.level = @level

      env[RACK_LOGGER] = logger
      @app.call(env)
    end