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: sspi.rb
    path of file: ./repos/ruby-packer/ruby/ext/win32/lib/win32
    
    the code of the file until where you have to start completion: # frozen_string_literal: false
#
# = win32/sspi.rb
#
# Copyright (c) 2006-2007 Justin Bailey
#
# Written and maintained by Justin Bailey <jgbailey@gmail.com>.
#
# This program is free software. You can re-distribute and/or
# modify this program under the same terms of ruby itself ---
# Ruby Distribution License 
    
			def NegotiateAuth.proxy_auth_get(http, path, user = nil, domain = nil)
				raise "http must respond to :get" unless http.respond_to?(:get)
				nego_auth = self.new user, domain

				resp = http.get path, { "Proxy-Authorization" => "Negotiate " + nego_auth.get_initial_token }
				if resp["Proxy-Authenticate"]
					resp = http.get path, { "Proxy-Authorization" => "Negotiate " + nego_auth.complete_authentication(resp["Proxy-Authenticate"].split(" ").last.strip) }
				end

				resp
			end