call real syn funcs at least

src/syn.rs

@@ -77,7 +77,16 @@ mod test {
 
    #[test]
    fn test_new_real() {
-      Syn::new(false, "super_small_font.sf2".to_string(), 44100);
+      let mut syn = Syn::new(false, "super_small_font.sf2".to_string(), 44100);
+
+      syn.note_on(1, 2, 3);
+      syn.note_on(2, 3, 4);
+
+      syn.note_off(2, 3);
+
+      let mut buffer1 = Vec::<f32>::new();
+      let mut buffer2 = Vec::<f32>::new();
+      syn.render(&mut buffer1, &mut buffer2);
    }
 
    #[test]