[HELP] can we set multiple extended packages??

[白鹏]

<package name="project" extends="struts-default">
       here defines the *authorityStack *
</package>
<package name="a" extends="project,json-default">
  <default-interceptor ref-name="*authorityStack*"/>   // but the debugger
told me it* could not find the authorityStack!*
</package>

Does anyone can help?

Thanks !