question: public Pnt extend ( double ... coords ) { double [ ] result = new double [ coordinates . length + coords . length ] ; System . arraycopy ( coordinates , 0 , result , 0 , coordinates . length ) ; System . arraycopy ( coords , 0 , result , coordinates . length , coords . length ) ; return new Pnt ( result ) ; }
target:  Create a new Pnt by adding additional coordinates to this Pnt.