feat(plugins): update tests

agent-api/src/test/java/com/intergral/deep/agent/api/spi/IDeepPluginTest.java

@@ -0,0 +1,34 @@
+/*
+ *     Copyright (C) 2023  Intergral GmbH
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU Affero General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU Affero General Public License for more details.
+ *
+ *     You should have received a copy of the GNU Affero General Public License
+ *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.intergral.deep.agent.api.spi;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import org.junit.jupiter.api.Test;
+
+class IDeepPluginTest {
+
+  @Test
+  void configure() {
+    final IDeepPlugin iDeepPlugin = new IDeepPlugin() {
+    };
+    assertNotNull(iDeepPlugin.configure(null, null));
+    assertSame(iDeepPlugin, iDeepPlugin.configure(null, null));
+  }
+}

agent/src/main/java/com/intergral/deep/agent/plugins/PluginSpiLoader.java

@@ -31,7 +31,10 @@
 /**
  * This acts as the main loader for plugins using the SPI loader system.
  */
-public class PluginSpiLoader {
+public final class PluginSpiLoader {
+
+  private PluginSpiLoader() {
+  }
 
   // Visible for testing
   static final String ENABLED_PLUGIN_KEY = "deep.java.enabled.plugin";