优化获取请求-通过运输go更改RoundTripper

I reach a limit in the number of requests I can get using the default httpClient that my API wrapper provides.

//I was getting something like this at the beginning
Head www.example.com:80/: lookup example.com: no such host

To solve this I want to change the MaxIdleConnsPerHost setting for the httpClient.Transport of my client. It looks much more like this: However, the Transport my client uses is a RoundTripper and subsequently, it doesn't have a MaxIdleConnsPerHost param.

&oauth2.Transport{Source:(*oauth2.reuseTokenSource)(0xc2082ac0c0), 
              Base:http.RoundTripper(nil), 
              mu:sync.Mutex{state:0, sema:0x0}, 
              modReq:map[*http.Request]*http.Request(nil)
              }

The one I'm providing is mostly a default one and it lacks the proper configuration I suppose or simple what I want to do is not feasible.

&http.Transport{idleMu:sync.Mutex{state:0, sema:0x0}, 
                         idleConn:map[http.connectMethodKey][]*http.persistConn(nil), 
                         idleConnCh:map[http.connectMethodKey]chan *http.persistConn(nil), 
                         reqMu:sync.Mutex{state:0, sema:0x0}, 
                         reqCanceler:map[*http.Request]func()(nil), 
                         altMu:sync.RWMutex{w:sync.Mutex{state:0, sema:0x0}, 
                         writerSem:0x0, 
                         readerSem:0x0, 
                         readerCount:0, 
                         readerWait:0}, 
                         altProto:map[string]http.RoundTripper(nil), 
                         Proxy:(func(*http.Request) (*url.URL, error))(nil), 
                         Dial:(func(string, string) (net.Conn, error))(nil), 
                         TLSClientConfig:(*tls.Config)(nil), 
                         TLSHandshakeTimeout:0, 
                         DisableKeepAlives:false, 
                         DisableCompression:false, 
                         MaxIdleConnsPerHost:200, 
                         ResponseHeaderTimeout:0}

Can someone guide me on the right direction?