OOP - Method and Property bubbling in PHP

Bubbler.php

<?php
	/**
	 * BUBBLER CLASS
	 *
	 *	The Magic Methods __get, __set and __call are called by PHP when the object cannot
	 *	find or access methods or properties within the object, the Bubbler class intercepts
	 *	these and simply routes them to their "parent" object.
	 *
	 *			+--------------------------------------+
	 *			| Object A         /\    Plain Object  |
	 *			| +---------------|  |---------------+ |
	 *			| | Object B      |  |       Bubbler | |
	 *			| | +-------------|  |-------------+ | |
	 *			| | | Object C    |  |     Bubbler | | |
	 *			| | +------------------------------+ | |
	 *			| +----------------------------------+ |
	 *			|            METHOD BUBBLING           |
	 *			|           PROPERTY BUBBLING          |
	 *			+--------------------------------------+
	 *
	 *	This class was created for a query builder. The main class contained the database
	 *	handler and some schemata relating to the database structure. The child classes
	 *	were sql(), select(), upsert() and delete() - I wanted each of which to be fully chainable
	 *	and also to be able to access the parent database handler and schemata and I didn't
	 *	want any OTT engineering. In my query builder you can do these:
	 *
	 *		query->sql('SELECT TABLES')->execute()->debug();
	 *		query->select('*')->from('users')->join('avatar')->where('id', 1)->limit(1)->execute()->debug();
	 *		query->delete()->from('users')->where('id', 10)->limit(1)->execute()->debug();
	 *		query->upsert('users')->data(array( 'id'=>NULL, 'email'=>'david@oodavid.com' ))->return(TRUE)->execute()->debug();
	 *
	 *	As you can see, each use execute() and debug(), lets explain what happens:
	 *		execute() is defined as methods on the child objects sql, select, upsert and delete
	 *			They each build a SQL variable and store it as a property on the parent query object.
	 *			They also access the parents database handler and execute the query.
	 *		debug() however is NOT defined on any of the child objects, thus the method bubbles up to the parent query object.
	 *			Since the child objects have set the SQL property, this common method runs an analysis of the query showing timings,
	 *			bottlenecks etc. etc.
	 *
	 * @author		David King
	 * @copyright	Copyright (c) 2013 +
	 */
	class Bubbler{
		var $that;
		public function __construct(&$that){
			// Store the reference to the "parent" object
			$this->that = &$that;
		}
		public function __get($name){
			// Return the "parent" property if it exists
			if(property_exists($this->that, $name)){
				return $this->that->$name;
			}
		}
		public function __set($name, $value){
			// Set it on the parent property if it exists
			if(property_exists($this->that, $name)){
				$this->that->$name = $value;
			} else {
				$this->$name = $value;
			}
		}
		public function __call($name, $args){
			// Try and call it on the $that "parent"...
			if(is_callable(array($this->that, $name))){
				return call_user_func_array(array($this->that, $name), $args);
			}
		}
	}
	/**
	 * EXAMPLE
	 *
	 *	This example outputs the following:
	 *
	 *		I am ObjectA and my name is: David King
	 *		I am ObjectB and I am going to call sayMyName() - since I don't have that method it bubbles up to Object A, look:
	 *		      I am ObjectA and my name is: David King
	 *		I am ObjectC and I will try to access a property I don't have, again it will bubble up to ObjectA... My Name is: David King
	 */
	class ObjectA{
		var $name;
		public function __construct($name){
			// Store the name
			$this->name = $name;
		}
		public function sayMyName(){
			// Echo the name and return this for chaining
			echo "I am ObjectA and my name is: {$this->name}\n";
			return $this;
		}
		public function B(){
			// Create and return an instance of ObjectB
			$tmp = new ObjectB(&$this);
			return $tmp;
		}
		public function C(){
			// Create and return an instance of ObjectC
			$tmp = new ObjectC(&$this);
			return $tmp;
		}
	}
	class ObjectB extends Bubbler{
		public function saySomething(){
			// Say something and return this for chaining
			echo "I am ObjectB and I am going to call sayMyName() - since I don't have that method it bubbles up to Object A, look:\n      ";
			$this->sayMyName();
			return $this;
		}
	}
	class ObjectC extends Bubbler{
		public function saySomething(){
			// Say something and return this for chaining
			echo "I am ObjectC and I will try to access a property I don't have, again it will bubble up to ObjectA... My Name is: {$this->name}\n";
			// return this for chaining
			return $this;
		}
	}
	$objectA = new ObjectA('David King');
	$objectA->sayMyName()->B()->saySomething()->C()->saySomething();