if (ly_is_procedure (creation_callback))
scm_apply_0 (creation_callback,
scm_list_n (grob->self_scm (), scm_from_utf8_string (file),
if (ly_is_procedure (creation_callback))
scm_apply_0 (creation_callback,
scm_list_n (grob->self_scm (), scm_from_utf8_string (file),