Random failures due to MagicKey

There is a fixed 1000-iteration loop to find out proper key. In tests that create many magic keys, the cumulative probability of failing one of the keys' generation is going up and this is causing random failures in the testsuite.

Moreover, the equality of magic keys is based only on the hashCode - with many keys, there is a non-trivial chance that the hashcodes will make two logically different keys equal.