mongo to mongodb php driver migration helpers

MongoIdShim.php

<?php

class MongoId implements Serializable, JsonSerializable
{
    public $id;

    public function __construct($id)
    {
        $this->id = (string) $id;
    }

    public function getObjectId()
    {
        return new MongoDB\BSON\ObjectID($this->id);
    }

    public function serialize()
    {
        return serialize($this->id);
    }

    public function jsonSerialize()
    {
        return (string) $this->id;
    }

    public function unserialize($id)
    {
        $this->id = (string) $id;
    }

    public function __toString()
    {
        return (string) $id;
    }
}