"Unable to find operation run(java.lang.Runnable)" when using a ThreadPool from an MBean

Issue

When I try to have my MBean use an injected thread pool, I get the following exception:

java.lang.IllegalArgumentException: Unable to find operation run(java.lang.Runnable)
  at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:231)
  at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:659)
  at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:210)
  at $Proxy117.run(Unknown Source)
  at MyTpExample.run



<?xml version="1.0" encoding="UTF-8"?>
<server>
    <mbean code="org.jboss.util.threadpool.BasicThreadPool" name="example:service=ThreadPool">
        <attribute name="Name">My Thread Pool</attribute>
        <attribute name="KeepAliveTime">60000</attribute>
        <attribute name="MaximumPoolSize">10</attribute>
        <attribute name="MaximumQueueSize">100</attribute>
        <attribute name="BlockingMode">wait</attribute>
    </mbean>

    <mbean code="MyTpExample" name="example:service=MyService">
        <depends optional-attribute-name="ThreadPool" proxy-type="attribute">example:service=ThreadPool</depends>
    </mbean>
</server>



public class MyTpExample implements MyTpExampleMBean {
    private ThreadPool threadPool;

    public void setThreadPool(ThreadPool pool) {
        this.threadPool = pool;

        threadPool.run(new MyTask());
    }


    public static class MyTask implements Runnable {
        public void run() {
            System.out.println("running task");
        }

    }
}