function testAdd() {
    $hash = new Hash;
    assert($OK == $hash->add("foo","bar"));
}
function testGet() {
    $hash = new Hash;
    $hash->add("foo","bar");
    assert("bar" == $hash->get("foo"));
}
function testList() {
    $hash = new Hash;
    $hash->add("foo","bar");
    assert("foo" == $hash->listKeys());
}
function testRemove() {
    $hash = new Hash;
    $hash->add("foo","bar");
    assert($OK == $hash->remove("foo"));
}

##</code><code>##

function testGetShouldNotDieHorriblyIfKeyNotFound() {
    $hash = new Hash;
    $hash->get("foo");   # this was causing a core dump
}
function testRemoveShouldAcctuallyRemove() {
    $hash = new Hash;
    $hash->add("foo","bar");
    $hash->remove("foo");
    assert("bar" != $hash->get("foo"));  # hey look, still there
}