使用名称空间遍历xml中的元素

Question

I want to operate with XMPP users with github.com/mattn/go-xmpp Golang package. I change a little official example and got something like this:

switch v := chat.(type) {
case xmpp.IQ:
    if len(v.Query) != 0 {
        fmt.Printf("Query: %s", v.Query)
    }
default:
    fmt.Printf("detect default type: %T
", v)
}

v.Query is a XML document with namespace like

<query xmlns="jabber:iq:roster">
<item jid="JID1" name="Name" subscription="none" ask="subscribe">
    <group></group>
</item>
<item jid="JID2" name="Another name" subscription="both">
    <group>Group</group>
</item>
<item jid="JID3" name="Eman" subscription="both">
    <group>AnotherGroup</group>
</item>
</query>

How can I parse this document and iterate over jid elements?