<?php
/**
* PHP Document Object plus
*
* PHP Document Object plus is library with functionality of PDO, entirely written
* in PHP, so that developer can easily extend it's classes with specific functionality,
* such as providing database usage statistics implemented in v1.0b
*
* @author Peter Pokojny
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*/
    class PDOp {
        protected $PDO;
        public $numExecutes;
        public $numStatements;
        public function __construct($dsn, $user=NULL, $pass=NULL, $driver_options=NULL) {
            $this->PDO = new PDO($dsn, $user, $pass, $driver_options);
            $this->numExecutes = 0;
            $this->numStatements = 0;
        }
        public function __call($func, $args) {
            return call_user_func_array(array(&$this->PDO, $func), $args);
        }
        public function prepare() {
            $this->numStatements++;

            $args = func_get_args();
            $PDOS = call_user_func_array(array(&$this->PDO, 'prepare'), $args);

            return new PDOpStatement($this, $PDOS);
        }
        public function query() {
            $this->numExecutes++;
            $this->numStatements++;

            $args = func_get_args();
            $PDOS = call_user_func_array(array(&$this->PDO, 'query'), $args);

            return new PDOpStatement($this, $PDOS);
        }
        public function exec() {
            $this->numExecutes++;

            $args = func_get_args();
            return call_user_func_array(array(&$this->PDO, 'exec'), $args);
        }
    }
    class PDOpStatement implements IteratorAggregate {
        protected $PDOS;
        protected $PDOp;
        public function __construct($PDOp, $PDOS) {
            $this->PDOp = $PDOp;
            $this->PDOS = $PDOS;
        }
        public function __call($func, $args) {
            return call_user_func_array(array(&$this->PDOS, $func), $args);
        }
        public function bindColumn($column, &$param, $type=NULL) {
            if ($type === NULL)
                $this->PDOS->bindColumn($column, $param);
            else
                $this->PDOS->bindColumn($column, $param, $type);
        }
        public function bindParam($column, &$param, $type=NULL) {
            if ($type === NULL)
                $this->PDOS->bindParam($column, $param);
            else
                $this->PDOS->bindParam($column, $param, $type);
        }
        public function execute() {
            $this->PDOp->numExecutes++;
            $args = func_get_args();
            return call_user_func_array(array(&$this->PDOS, 'execute'), $args);
        }
        public function __get($property) {
            return $this->PDOS->$property;
        }
        public function getIterator() {
            return $this->PDOS;
        }
   }
?>

Classes have properties with original PDO and PDOStatement objects, which are providing the functionality to PDOp and PDOpStatement.
From outside, PDOp and PDOpStatement look like PDO and PDOStatement, but also are providing wanted info.