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: winhttp.go
    path of file: ./repos/sliver/implant/sliver/winhttp
    
    the code of the file until where you have to start completion: // +build windows

// Copyright (C) 2018, Rapid7 LLC, Boston, MA, USA.
// All rights reserved. This material contains unpublished, copyrighted
// work including confidential and proprietary information of Rapid7.
    
func GetDefaultProxyConfiguration() (*ProxyInfo, error) {
	pInfo := new(ProxyInfo)
	getDefaultProxyConfigurationP, err := whd.FindProc("WinHttpGetDefaultProxyConfiguration")
	if err != nil {
		return nil, err
	}
	r, _, err := getDefaultProxyConfigurationP.Call(uintptr(unsafe.Pointer(pInfo)))
	if rTrue(r) {
		return pInfo, nil
	}
	return nil, err
}