-ADD_ACKNOWLEDGER (Auto_beam_engraver,stem);
-ADD_ACKNOWLEDGER (Auto_beam_engraver,bar_line);
-ADD_ACKNOWLEDGER (Auto_beam_engraver,beam);
-ADD_ACKNOWLEDGER (Auto_beam_engraver,rest);
+ADD_ACKNOWLEDGER (Auto_beam_engraver, stem);
+ADD_ACKNOWLEDGER (Auto_beam_engraver, bar_line);
+ADD_ACKNOWLEDGER (Auto_beam_engraver, beam);
+ADD_ACKNOWLEDGER (Auto_beam_engraver, rest);