(PECL mongo >= 0.9.0)
MongoDBRef::isRef — Checks if an array is a database reference
This method does not actually follow the reference, so it does not determine if it is
broken or not. It merely checks that
ref is in valid
database reference format (in that it is an object or array with $ref and $id
Array or object to check.
TRUE on success or
FALSE on failure.