New in version 1.2.
Definition
Return Values
A MongoDB\Driver\ReadConcern object.
Example
$database = (new MongoDB\Client)->getDatabase('test', [    'readConcern' => new MongoDB\Driver\ReadConcern('majority'), ]); var_dump($database->getReadConcern()); 
The output would then resemble:
object(MongoDB\Driver\ReadConcern)#5 (1) {   ["level"]=>   string(8) "majority" }