reverted:
--- b/tests/src/Unit/HttpClientTest.php
+++ a/tests/src/Unit/HttpClientTest.php
@@ -187,7 +187,7 @@
    * @return array
    *   An array of command names.
    */
+  public function providerTestGetCommand() {
-  public static function providerTestGetCommand() {
     return [
       ['FindPost'],
       ['FindPosts'],