diff --git a/adaptor/README.md b/adaptor/README.md
new file mode 100644
index 0000000..a0510ce
--- /dev/null
+++ b/adaptor/README.md
@@ -0,0 +1,13 @@
+## Note:
+
+- When modifying the resp header in the server handler, please use `write` function to write the header. Otherwise, the modification will not take effect.
+
+```go
+func handler(resp http.ResponseWriter, req *http.Request) {
+    resp.Header().Add("Content-Encoding", "test")
+    _, err := resp.Write([]byte("Content-Encoding: test\n"))
+    if err != nil {
+        panic(err)
+    }
+}
+```
\ No newline at end of file
diff --git a/adaptor/handler_test.go b/adaptor/handler_test.go
index 5c0ff89..e2e345f 100644
--- a/adaptor/handler_test.go
+++ b/adaptor/handler_test.go
@@ -43,7 +43,6 @@ package adaptor
 
 import (
 	"context"
-	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -478,16 +477,10 @@ func TestFile(t *testing.T) {
 		assert.NotEqual(t, req.Header.Get("Content-Type"), "application/x-www-form-urlencoded")
 
 		err := req.ParseForm()
-		if err != nil {
-			fmt.Println(err)
-			panic(err)
-		}
+		assert.Nil(t, err)
 
 		file, m, err := req.FormFile("file")
-		if err != nil {
-			fmt.Println(err)
-			panic(err)
-		}
+		assert.Nil(t, err)
 
 		assert.DeepEqual(t, m.Filename, "handler.go")