docs: net/anyhttp: add comments

net/anyhttp/fasthttp.go

@@ -63,6 +63,11 @@ func (w ResponseFastHttp) SetBodyBytes(body []byte) (int, error) {
 	w.Raw.SetBody(body)
 	return -1, nil
 }
+
+// SetBodyStream takes an `io.Reader` and an optional `bodySize`.
+// If bodySize is >= 0, then bodySize bytes must be provided by
+// bodyStream before returning io.EOF. If bodySize < 0, then
+// bodyStream is read until io.EOF.
 func (w ResponseFastHttp) SetBodyStream(bodyStream io.Reader, bodySize int) error {
 	w.Raw.SetBodyStream(bodyStream, bodySize)
 	return nil

net/anyhttp/nethttp.go

@@ -93,6 +93,9 @@ func (w ResponseNetHttp) SetBodyBytes(body []byte) (int, error) {
 	w.Raw.Write(body)
 	return -1, nil
 }
+
+// SetBodyStream takes an `io.Reader`. `bodySize` is accepted but
+// ignored to fulfill the `Response` interface requirement.
 func (w ResponseNetHttp) SetBodyStream(bodyStream io.Reader, bodySize int) error {
 	bytes, err := ioutil.ReadAll(bodyStream)
 	if err != nil {