question: public Frame copy ( ) { Frame frame = new Frame ( locals . length , stack . length ) ; System . arraycopy ( locals , 0 , frame . locals , 0 , locals . length ) ; System . arraycopy ( stack , 0 , frame . stack , 0 , stack . length ) ; frame . top = top ; return frame ; }
target:  Makes a shallow copy of this frame, i.e. the type instances will remain the same.