/**
* Verifies that we get an exception if there appears to be a key
* collision.
*/
public function testKeyCollision()
{
$mutex = new Mutex($this);
$lockID = $mutex->getLockID();
/* Passing the key manually should cause an error, because the code
will know that the first time this key was used, it was automatically
derived. */
$this->assertThrows('MutexException', function () use($lockID) {
new Mutex($lockID);
}, null, 'Instantiating a new Mutex with a value that causes a key collision failed to raise the expected exception.');
}
