When I set up the mapping for collections with class prefix, the documents class are set by default with 'Sokil\Mongo\Document'

Now in custom collections I can set documentClass field, but this field is @deprecated
@deprecated since 1.13 Use 'documentClass' declaration in mapping

I think it would be good to add also document class prefix in mapping, where there are many collections to define.

$client->map([
    'databaseName'  => array(
        collectionsPrefix => '\Class\Prefix',
        documentsPrefix => '\Class\DocumentPrefix',
     ),
]);