public static void main( String [ ] args )
 {
     RedBlackTree<Integer> t = new RedBlackTree<>( );
     final int NUMS = 400000;
     final int GAP  =  35461;

     System.out.println( "Checking... (no more output means success)" );

     for( int i = GAP; i != 0; i = ( i + GAP ) % NUMS )
         t.insert( i );

     if( t.findMin( ) != 1 || t.findMax( ) != NUMS - 1 )
         System.out.println( "FindMin or FindMax error!" );

     for( int i = 1; i < NUMS; i++ )
          if( !t.contains( i ) )
              System.out.println( "Find error1!" );
 }