Add Root namespace for Cassandra class

cassandra/cassandra.php

@@ -26,6 +26,8 @@
  * limitations under the License.
  */
 
+namespace {
+
     /**
      * The main entry point to the PHP Driver for Apache Cassandra.
      *
@@ -464,6 +466,8 @@ final class Cassandra
 
     }
 
+}
+
 
 /**
  * @link https://docs.datastax.com/en/developer/php-driver/latest/api/Cassandra/