question: public final void testSetSeedbyteArray03 ( ) throws NoSuchFieldException , SecurityException , IllegalAccessException { byte [ ] seed = new byte [ LENGTH ] ; byte [ ] bytes1 ; byte [ ] bytes2 ; for ( int i = 0 ; i < seed . length ; i ++ ) { seed [ i ] = ( byte ) i ; } for ( int i = 0 ; i < LENGTH ; i ++ ) { bytes1 = new byte [ i ] ; bytes2 = new byte [ i ] ; sr . setSeed ( seed ) ; sr . setSeed ( new byte [ 0 ] ) ; sr . nextBytes ( bytes1 ) ; sr2 . setSeed ( seed ) ; sr2 . nextBytes ( bytes2 ) ; for ( int j = 0 ; j < bytes1 . length ; j ++ ) { assertEquals ( "bytes1[j] != bytes2[j] :: j=" + j , bytes1 [ j ] , bytes2 [ j ] ) ; } } for ( int i = 1 ; i < LENGTH ; i ++ ) { bytes1 = new byte [ i ] ; bytes2 = new byte [ i ] ; sr . setSeed ( seed ) ; sr . nextBytes ( bytes1 ) ; sr . setSeed ( new byte [ 0 ] ) ; sr . nextBytes ( bytes2 ) ; boolean b = true ; for ( int j = 0 ; j < bytes1 . length ; j ++ ) { b &= bytes1 [ j ] == bytes2 [ j ] ; } assertFalse ( "sequences are equal i=" + i , b ) ; } }
target:  test against the "void setSeed(byte[])" method; it checks out that the "byte[0]" argument has no effect; there are two testcases: - if one of two SecureRandom objects supplied with the same seed is additionally supplied with such array, "nextBytes(..)" of both objects return the same bytes; - two byte arrays returned by "nextBytes(..)" in following sequence nextBytes(..); setSeed(new byte[0]); nextBytes(..); don't contain the same byte sequencies.