@Test
public void cantGetLockForTheSameKeyFromParallelTransaction() {

    keyLocker.writeLock( "abc", transactionID, 0, true );
    assertThat( keyLocker.writeLock( "abc", transactionID + 1, 1, true ), is( nullValue() ) );
    assertThat( keyLocker.writeLock( "abc", transactionID + 2, 0, true ), is( nullValue() ) );
}