public function testCount()
{
$this->assertCount(0, $this->collection);
$this->collection->add(new Command(new CommandConfig('ls')));
$this->assertCount(1, $this->collection);
$this->collection->add(new Command(new CommandConfig('cd')));
$this->assertCount(2, $this->collection);
$this->collection->remove('ls');
$this->assertCount(1, $this->collection);
$this->collection->clear();
$this->assertCount(0, $this->collection);
}