/**
* Tests the is_empty() function.
*/
public function test_is_empty()
{
// Tree with nothing in should be empty.
$structure = tree::get_root_json(array(), tree::OP_OR);
$tree = new tree($structure);
$this->assertTrue($tree->is_empty());
// Tree with something in is not empty.
$structure = tree::get_root_json(array(self::mock(array('m' => '1'))), tree::OP_OR);
$tree = new tree($structure);
$this->assertFalse($tree->is_empty());
}
