question: protected void beforeInsertDummies ( int index , int length ) { if ( index > size || index < 0 ) throw new IndexOutOfBoundsException ( "Index: " + index + ", Size: " + size ) ; if ( length > 0 ) { ensureCapacity ( size + length ) ; System . arraycopy ( elements , index , elements , index + length , size - index ) ; size += length ; } }
target:  Inserts length dummies before the specified position into the receiver.  Shifts the element currently at that position (if any) and any subsequent elements to the right.