Description:
------------
The MongoCollection::batchInsert method raises a MongoDuplicateKeyException even while using the continueOnError flag. This affects the example because there is no try catch construct.

In the test script form I show a simple correction.

Test script:
---------------
$con = new MongoClient;
// rest of the code
$c = $db->selectCollection('c');
try {
$c->batchInsert(
    array($doc1, $doc2, $doc3, $doc4),
    array('continueOnError' => true)
);
} catch(MongoDuplicateKeyException $e) {
}