Issue checkstyle#11514: add test case for base cell editor

src/test/java/com/puppycrawl/tools/checkstyle/gui/BaseCellEditorTest.java

@@ -0,0 +1,41 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
+// Copyright (C) 2001-2023 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+///////////////////////////////////////////////////////////////////////////////////////////////
+
+package com.puppycrawl.tools.checkstyle.gui;
+
+import static com.google.common.truth.Truth.assertWithMessage;
+
+import org.junit.jupiter.api.Test;
+
+import javax.swing.event.CellEditorListener;
+
+
+class BaseCellEditorTest {
+
+    private BaseCellEditor bce = new BaseCellEditor();
+
+    @Test
+    void testToString() {
+        assertWithMessage("is null")
+                .that(bce.getCellEditorValue() == null)
+                .isEqualTo(true);
+    }
+
+
+}