Add return types to internal|final|private methods

Author: nicolas-grekas

Adapter/ExtLdap/Query.php

@@ -169,7 +169,7 @@ public function getResource($idx = 0)
      *
      * @internal
      */
-    public function getResources()
+    public function getResources(): array
     {
         return $this->results;
     }

Security/LdapUser.php

@@ -57,22 +57,22 @@ public function getRoles()
     /**
      * {@inheritdoc}
      */
-    public function getPassword()
+    public function getPassword(): ?string
     {
         return $this->password;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function getSalt()
+    public function getSalt(): ?string
     {
     }
 
     /**
      * {@inheritdoc}
      */
-    public function getUsername()
+    public function getUsername(): string
     {
         return $this->username;
     }