improve fuzz tests (#571)

pkg/base/interleaved_frame_test.go

@@ -55,6 +55,9 @@ func TestInterleavedFrameMarshal(t *testing.T) {
 }
 
 func FuzzInterleavedFrameUnmarshal(f *testing.F) {
+	for _, ca := range casesInterleavedFrame {
+		f.Add(ca.enc)
+	}
 	f.Fuzz(func(_ *testing.T, b []byte) {
 		var f InterleavedFrame
 		f.Unmarshal(bufio.NewReader(bytes.NewBuffer(b))) //nolint:errcheck