public function test_that_partition_returns_expected_sets()
{
$set = SortedSet::string();
$set->add('foo');
$set->add('bar');
$set->add('baz');
$parts = $set->partition(function ($item) {
return substr($item, 0, 1) === 'b';
});
$data1 = [];
foreach ($parts[0] as $item) {
$data1[] = $item;
}
$data2 = [];
foreach ($parts[1] as $item) {
$data2[] = $item;
}
$this->assertTrue(count($data1) === 2 && count($data2) === 1);
}
