Throw a RuntimeException subclass instead of RuntimeException

src/main/java/org/apache/commons/collections4/list/TreeList.java

@@ -686,7 +686,7 @@ public class TreeList<E> extends AbstractList<E> {
                 }
                 return rotateLeft();
             default :
-                throw new RuntimeException("tree inconsistent!");
+                throw new IllegalStateException("tree inconsistent!");
             }
         }
 

src/main/java/org/apache/commons/collections4/sequence/SequencesComparator.java

@@ -234,7 +234,7 @@ public class SequencesComparator<T> {
         }
 
         // this should not happen
-        throw new RuntimeException("Internal Error");
+        throw new IllegalStateException("Internal Error");
     }