--- /dev/null
+<?php
+
+namespace Drupal\settings_tray_test\Plugin\Block;
+
+use Drupal\Core\Block\BlockBase;
+
+/**
+ * Block that explicitly provides no "settings_tray" form, thus opting out.
+ *
+ * @Block(
+ * id = "settings_tray_test_false",
+ * admin_label = "Settings Tray test block: forms[settings_tray]=FALSE",
+ * forms = {
+ * "settings_tray" = FALSE,
+ * },
+ * )
+ */
+class SettingsTrayFormAnnotationIsFalseBlock extends BlockBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function build() {
+ return ['#markup' => '<span>FALSE</span>'];
+ }
+
+}