implemented just a better workaround for Xtend bug
https://bugs.eclipse.org/bugs/show_bug.cgi?id=430489, where warning
about unused method is issed, which in fact is used at the constructor;
now any user defined method name may be used instead of "bind" of the
former solution, only the annotation @Wiring must be added, then a call
to this method is added to function unit's constructor code