+ Else, move so dimension (A)[D] == 0.0
+
+ */
+ void align_to (Axis a, Direction d);
+ void translate_axis (Real,Axis);
+
+ Interval extent (Axis) const;
+ Box extent_box () const;
+ /**
+ codify THIS into a Scheme expression.
+ */
+ SCM create_scheme () const;
+ bool empty_b () const;
+
+
+ static SCM ly_get_molecule_extent (SCM mol, SCM axis);
+ static SCM ly_set_molecule_extent_x (SCM,SCM,SCM);
+ static SCM ly_molecule_combined_at_edge (SCM,SCM,SCM,SCM,SCM);