Feat Add headers to openai responses (#506)

* feat: add headers to http response

* chore: add test

* fix: rename to httpHeader

client.go

@@ -20,6 +20,20 @@ type Client struct {
 	createFormBuilder func(io.Writer) utils.FormBuilder
 }
 
+type Response interface {
+	SetHeader(http.Header)
+}
+
+type httpHeader http.Header
+
+func (h *httpHeader) SetHeader(header http.Header) {
+	*h = httpHeader(header)
+}
+
+func (h httpHeader) Header() http.Header {
+	return http.Header(h)
+}
+
 // NewClient creates new OpenAI API client.
 func NewClient(authToken string) *Client {
 	config := DefaultConfig(authToken)
@@ -82,7 +96,7 @@ func (c *Client) newRequest(ctx context.Context, method, url string, setters ...
 	return req, nil
 }
 
-func (c *Client) sendRequest(req *http.Request, v any) error {
+func (c *Client) sendRequest(req *http.Request, v Response) error {
 	req.Header.Set("Accept", "application/json; charset=utf-8")
 
 	// Check whether Content-Type is already set, Upload Files API requires
@@ -103,6 +117,10 @@ func (c *Client) sendRequest(req *http.Request, v any) error {
 		return c.handleErrorResp(res)
 	}
 
+	if v != nil {
+		v.SetHeader(res.Header)
+	}
+
 	return decodeResponse(res.Body, v)
 }