function run_component_proba()
{
// Create a tree structure
$root = new Composite("root");
$root->Add(new Leaf("Leaf A"));
$root->Add(new Leaf("Leaf B"));
$comp = new Composite("Composite X");
$comp->Add(new Leaf("Leaf XA"));
$comp->Add(new Leaf("Leaf XB"));
$root->Add($comp);
$root->Add(new Leaf("Leaf C"));
// Add and remove a leaf
$leaf = new Leaf("Leaf D");
$root->Add($leaf);
$root->Remove($leaf);
// Recursively display tree
$root->Display();
}
