question: public IVector2D ( int [ ] [ ] v ) { defaultCapacity2 = defaultDefaultCapacity2 ; if ( v . length == 0 ) { vector = new int [ defaultCapacity1 ] [ defaultCapacity2 ] ; sizes = new IVector ( defaultCapacity1 ) ; } else { vector = v ; sizes = new IVector ( v . length ) ; for ( int i = 0 ; i < v . length ; ++ i ) { sizes . set ( i , v [ i ] . length ) ; defaultCapacity2 = Math . max ( defaultCapacity2 , v [ i ] . length ) ; } for ( int i = 0 ; i < v . length ; ++ i ) if ( v [ i ] . length == 0 ) v [ i ] = new int [ defaultCapacity2 ] ; } }
target:  Constructs a new vector using the specified array as a starting point.