question: public E remove ( int index ) { hashCodeUpToDate = false ; modCount ++ ; E oldValue = elementData ( index ) ; int numMoved = size - index - 1 ; if ( numMoved > 0 ) System . arraycopy ( elementData , index + 1 , elementData , index , numMoved ) ; elementData [ -- size ] = null ; return oldValue ; }
target:  Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices).