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: proxy.go
    path of file: ./repos/client/go/libkb
    
    the code of the file until where you have to start completion: /*

Proxy support is implemented using golang's http library's built in support for proxies. This supports http connect
based proxies and socks5 proxies. Proxies can be configured using: CL
    
func ProxyHTTPClient(g *GlobalContext, env *Env, instrumentationTag string) *http.Client {
	xprt := NewInstrumentedRoundTripper(g, func(*http.Request) string { return instrumentationTag },
		&http.Transport{
			Proxy: MakeProxy(env),
		})
	client := &http.Client{
		Transport: xprt,
	}
	return client
}