question: @ Override public boolean equals ( Object obj ) { if ( obj == this ) { return true ; } if ( ! ( obj instanceof KeyedObjects ) ) { return false ; } KeyedObjects that = ( KeyedObjects ) obj ; int count = getItemCount ( ) ; if ( count != that . getItemCount ( ) ) { return false ; } for ( int i = 0 ; i < count ; i ++ ) { Comparable k1 = getKey ( i ) ; Comparable k2 = that . getKey ( i ) ; if ( ! k1 . equals ( k2 ) ) { return false ; } Object o1 = getObject ( i ) ; Object o2 = that . getObject ( i ) ; if ( o1 == null ) { if ( o2 != null ) { return false ; } } else { if ( ! o1 . equals ( o2 ) ) { return false ; } } } return true ; }
target:  Tests this object for equality with an arbitrary object.