Interfaces were created in the order the appears in the ISO 19107 specification, up to (only partially included) GM_Conic. The rest of Java interfaces for geometries need to be created using the skeleton already available.
Special care must be taken regarding javadoc. The ISO 19107 has a very accurate documentation, with a fair amount of figures and equations. Javadoc is the longuest task during Java interface creation, and should not be skipped.