Fix SpotBugs errors

- [ERROR] Medium: org.apache.commons.io.IOExceptionList.getCauseList()
may expose internal representation by returning
IOExceptionList.causeList [org.apache.commons.io.IOExceptionList] At
IOExceptionList.java:[line 118] EI_EXPOSE_REP
- [ERROR] Medium:
org.apache.commons.io.IOExceptionList.getCauseList(Class) may expose
internal representation by returning IOExceptionList.causeList
[org.apache.commons.io.IOExceptionList] At IOExceptionList.java:[line
129] EI_EXPOSE_REP

Author: garydgregory

src/changes/changes.xml

@@ -62,6 +62,8 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix" due-to="Gary Gregory">Fix SpotBugs error: Class org.apache.commons.io.monitor.FileAlterationObserver defines non-transient non-serializable instance field fileFilter [org.apache.commons.io.monitor.FileAlterationObserver] In FileAlterationObserver.java SE_BAD_FIELD.</action>
       <action dev="ggregory" type="fix" due-to="Gary Gregory">Fix SpotBugs error: Class org.apache.commons.io.monitor.FileAlterationObserver defines non-transient non-serializable instance field listeners [org.apache.commons.io.monitor.FileAlterationObserver] In FileAlterationObserver.java SE_BAD_FIELD.</action>
       <action dev="ggregory" type="fix" due-to="Gary Gregory">Fix SpotBugs error: org.apache.commons.io.FileCleaningTracker.getDeleteFailures() may expose internal representation by returning FileCleaningTracker.deleteFailures [org.apache.commons.io.FileCleaningTracker] At FileCleaningTracker.java:[line 218] EI_EXPOSE_REP.</action>
+      <action dev="ggregory" type="fix" due-to="Gary Gregory">Fix SpotBugs error: org.apache.commons.io.IOExceptionList.getCauseList() may expose internal representation by returning IOExceptionList.causeList [org.apache.commons.io.IOExceptionList] At IOExceptionList.java:[line 118] EI_EXPOSE_REP.</action>
+      <action dev="ggregory" type="fix" due-to="Gary Gregory">Fix SpotBugs error: org.apache.commons.io.IOExceptionList.getCauseList(Class) may expose internal representation by returning IOExceptionList.causeList [org.apache.commons.io.IOExceptionList] At IOExceptionList.java:[line 129] EI_EXPOSE_REP.</action>
       <!-- UPDATE -->
       <action dev="ggregory" type="update" due-to="Gary Gregory">Bump org.codehaus.mojo:exec-maven-plugin from 3.1.0 to 3.1.1 #512.</action>
       <action dev="ggregory" type="update" due-to="Gary Gregory">Bump commons-lang3 from 3.13.0 to 3.14.0.</action>      

src/main/java/org/apache/commons/io/IOExceptionList.java

@@ -18,6 +18,7 @@
 package org.apache.commons.io;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -115,7 +116,7 @@ public <T extends Throwable> T getCause(final int index, final Class<T> clazz) {
      * @return The list of causes.
      */
     public <T extends Throwable> List<T> getCauseList() {
-        return (List<T>) causeList;
+        return (List<T>) new ArrayList<>(causeList);
     }
 
     /**
@@ -126,7 +127,7 @@ public <T extends Throwable> List<T> getCauseList() {
      * @return The list of causes.
      */
     public <T extends Throwable> List<T> getCauseList(final Class<T> clazz) {
-        return (List<T>) causeList;
+        return (List<T>) new ArrayList<>(causeList);
     }
 
     @Override