diff --git a/src/test/java/org/apache/commons/lang3/SE4560EighthTest.java b/src/test/java/org/apache/commons/lang3/SE4560EighthTest.java
new file mode 100644
index 00000000000..0233210fd4c
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/SE4560EighthTest.java
@@ -0,0 +1,53 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.lang3;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class SE4560EighthTest {
+    // Boundary value tests on RegExUtil's removeAll() methods
+    @Test
+    void removeAllNullTest() {
+        assertEquals(null, RegExUtils.removeAll(null, "[a-z]"));
+    }
+    @Test
+    void removeAllNormalTest() {
+        assertEquals("abc", RegExUtils.removeAll("ABCabc", "[A-Z]"));
+    }
+    @Test
+    void removeAllEmptyTest() {
+        assertEquals("", RegExUtils.removeAll("ABCabc", ".*"));
+    }
+    @Test
+    void removeAllSpecialCharTest() {
+        assertEquals("abc", RegExUtils.removeAll("a?bc", "\\?"));
+    }
+    @Test
+    void removeAllAnchorTest() {
+        assertEquals("BCabc", RegExUtils.removeAll("ABCabc", "^."));
+    }
+    @Test
+    void removeAllOrTest() {
+        assertEquals("Cc", RegExUtils.removeAll("ABCabc", "(ab)|(AB)"));
+    }
+    @Test
+    void removeAllRepeatingTest() {
+        assertEquals("ABCabc", RegExUtils.removeAll("ABCaaaabc", "a{3}"));
+    }
+}
diff --git a/src/test/java/org/apache/commons/lang3/SE4560NinthTest.java b/src/test/java/org/apache/commons/lang3/SE4560NinthTest.java
new file mode 100644
index 00000000000..2b5a4a04591
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/SE4560NinthTest.java
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.lang3;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class SE4560NinthTest {
+    // Boundary value tests on StringUtil's compare() method
+    @Test
+    void CompareNullTest() {
+        assertEquals(0, StringUtils.compare(null, null, true));
+        assertEquals(-1, StringUtils.compare(null, " ", true));
+        assertEquals(1, StringUtils.compare(null, " ", false));
+    }
+    @Test
+    void CompareNormalTest() {
+        assertEquals(3, StringUtils.compare("d", "a", true));
+    }
+    @Test
+    void CompareSpecialCharTest() {
+        assertEquals(53, StringUtils.compare("???", "\n", true));
+    }
+    @Test
+    void CompareEqualTest() {
+        assertEquals(0, StringUtils.compare("abc", "abc", true));
+    }
+    @Test
+    void CompareUpperTest() {
+        assertEquals(32, StringUtils.compare("abc", "ABC", true));
+    }
+    @Test
+    void CompareLengthTest() {
+        assertEquals(3, StringUtils.compare("abcabc", "abc", true));
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/org/apache/commons/lang3/SE4560SeventhTest.java b/src/test/java/org/apache/commons/lang3/SE4560SeventhTest.java
new file mode 100644
index 00000000000..5e10e1282a3
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/SE4560SeventhTest.java
@@ -0,0 +1,65 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.lang3;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class SE4560SeventhTest {
+    // Boundary value test on StringUtil's join() method
+    @Test
+    void JoinNullTest() {
+        String array[] = {null};
+        assertEquals("", StringUtils.join(array, "", 0, 0));
+    }
+    @Test
+    void JoinEmptyTest() {
+        String array[] = {};
+        assertEquals("", StringUtils.join(array, "", 0, 0));
+    }
+    @Test
+    void JoinNormalTest() {
+        String array[] = {"a", "b", "c"};
+        assertEquals("a,b,c", StringUtils.join(array, ",", 0, 3));
+    }
+    @Test
+    void JoinNumTest() {
+        Integer array[] = {1, 2, 3};
+        assertEquals("1,2,3", StringUtils.join(array, ",", 0, 3));
+    }
+    @Test
+    void JoinHighIndexTest() {
+        String array[] = {"a", "b", "c"};
+        assertEquals("a,b,c", StringUtils.join(array, ",", 0, 5));
+    }
+    @Test
+    void JoinLowIndexTest() {
+        String array[] = {"a", "b", "c"};
+        assertEquals("a", StringUtils.join(array, ",", 0, 1));
+    }
+    @Test
+    void JoinOutOfBoundsTest() {
+        String array[] = {"a", "b", "c"};
+        assertThrows(IllegalArgumentException.class, () -> {StringUtils.join(array, ",", -1, 3);});
+    }
+    @Test
+    void JoinNoIndexTest() {
+        String array[] = {"a", "b", "c"};
+        assertEquals("a,b,c", StringUtils.join(array, ","));
+    }
+}
diff --git a/src/test/java/org/apache/commons/lang3/SE4560TenthTest.java b/src/test/java/org/apache/commons/lang3/SE4560TenthTest.java
new file mode 100644
index 00000000000..db7455c0677
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/SE4560TenthTest.java
@@ -0,0 +1,57 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.lang3;
+
+import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
+
+public class SE4560TenthTest {
+    // Class partition tests on StringUtil's abbreviate() methods
+    @Test
+    void AbbreviateShortTest() {
+        assertEquals("abc", StringUtils.abbreviate("abc", 4));
+    }
+    @Test
+    void AbbreviateLongTest() {
+        assertEquals("a...", StringUtils.abbreviate("abcdefg", 4));
+    }
+    @Test
+    void AbbreviateNullTest() {
+        assertEquals(null, StringUtils.abbreviate(null, 4));
+    }
+    @Test
+    void AbbreviateNormalTest() {
+        assertEquals("abc...", StringUtils.abbreviate("abcdefghi", 6));
+    }
+    @Test
+    void AbbreviateInvalidTest() {
+        assertThrows(IllegalArgumentException.class, () -> {StringUtils.abbreviate("abc", 1);});
+    }
+    @Test
+    void AbbreviateOffsetTest() {
+        assertEquals("...abc...", StringUtils.abbreviate("12345abc12345", 5, 9));
+    }
+    @Test
+    void AbbreviateMarkerTest() {
+        assertEquals("-abc-", StringUtils.abbreviate("123abc123","-", 3, 5));
+    }
+    @Test
+    void AbbreviateMarkerInvalidTest() {
+        assertThrows(IllegalArgumentException.class, () -> {StringUtils.abbreviate("12345abc12345", ".....", 7, 10);});
+    }
+}