[Contracts/Service] Add generics to ServiceProviderInterface

Author: nicolas-grekas

Service/ServiceProviderInterface.php

@@ -18,9 +18,23 @@
  *
  * @author Nicolas Grekas <[email protected]>
  * @author Mateusz Sip <[email protected]>
+ *
+ * @template T of mixed
  */
 interface ServiceProviderInterface extends ContainerInterface
 {
+    /**
+     * {@inheritdoc}
+     *
+     * @return T
+     */
+    public function get(string $id): mixed;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function has(string $id): bool;
+
     /**
      * Returns an associative array of service types keyed by the identifiers provided by the current container.
      *