Declare $parameters property of Predis\Connection\Parameters (#781)

src/Connection/Parameters.php

@@ -26,6 +26,14 @@ class Parameters implements ParametersInterface
         'port' => 6379,
     );
 
+    /**
+     * Set of connection paramaters already filtered
+     * for NULL or 0-length string values.
+     * 
+     * @var array
+     */
+    protected $parameters;
+
     /**
      * @param array $parameters Named array of connection parameters.
      */