static bool has_axis (Grob *, Axis);
static void get_children (Grob *, vector<Grob*> *);
static Interval staff_extent (Grob *me, Grob *ref, Axis, Grob *staff, Axis);
static bool has_axis (Grob *, Axis);
static void get_children (Grob *, vector<Grob*> *);
static Interval staff_extent (Grob *me, Grob *ref, Axis, Grob *staff, Axis);