return errors.New("header appeared from after WriteHeader")
                                }
                                if !strings.Contains(got, "Content-Type: some/type") {
-                                       return errors.New("wrong content-length")
+                                       return errors.New("wrong content-type")
                                }
                                return nil
                        },
                        },
                        check: func(got string) error {
                                if !strings.Contains(got, "Content-Type: text/html") {
-                                       return errors.New("wrong content-length; want html")
+                                       return errors.New("wrong content-type; want html")
                                }
                                return nil
                        },
                        },
                        check: func(got string) error {
                                if !strings.Contains(got, "Content-Type: some/type") {
-                                       return errors.New("wrong content-length; want html")
+                                       return errors.New("wrong content-type; want html")
                                }
                                return nil
                        },
                        },
                        check: func(got string) error {
                                if !strings.Contains(got, "Content-Type: text/plain") {
-                                       return errors.New("wrong content-length; want text/plain")
+                                       return errors.New("wrong content-type; want text/plain")
                                }
                                if !strings.Contains(got, "Content-Length: 0") {
                                        return errors.New("want 0 content-length")