How to query for room information

In ‘XEP-0045: Multi-User Chat’, it describes that through the following method we can get the chat room information:

Example 6. User Queries for Information about a Specific Chat Room

<iq from=‘hag66@shakespeare.lit/pda’

id=‘disco3’

to=‘darkcave@macbeth.shakespeare.lit’

type=‘get’>

<query xmlns=’[http://jabber.org/protocol/disco#info|http://jabber.org/protocol/disco#info]’/>

</iq>

The room MUST return its identity and SHOULD return the features it supports:

Example 7. Room Returns Disco Info Results

<iq from=‘darkcave@macbeth.shakespeare.lit’

id=‘disco3’

to=‘hag66@shakespeare.lit/pda’

type=‘result’>

<query xmlns=’[http://jabber.org/protocol/disco#info|http://jabber.org/protocol/disco#info]’>

<identity

category=‘conference’

name=‘A Dark Cave’

type=‘text’/>

&lt;feature var='[http://jabber.org/protocol/muc|http://jabber.org/protocol/muc]'/>

<feature var=‘muc_passwordprotected’/>

<feature var=‘muc_hidden’/>

<feature var=‘muc_temporary’/>

<feature var=‘muc_open’/>

<feature var=‘muc_unmoderated’/>

<feature var=‘muc_nonanonymous’/>

</query>

</iq>

In my implementation, I send the following iq to query for room information:

<iq from=“fl@sysd-marry/agsXMPP”

id=“agsXMPP_8”

type=“get” to=“testroom@conference.sysd-marry”>

<query xmlns=“http://jabber.org/protocol/disco#info” />

</iq>

but the server return the following iq:

<iq xmlns=“jabber:client”

from=“testroom@conference.sysd-marry”

to=“fl@sysd-marry/agsXMPP”

type=“result”

id=“agsXMPP_8”>

<query xmlns=“http://jabber.org/protocol/disco#info”><feature var=“http://jabber.org/protocol/disco#info” />

</query>

</iq>

why it can’t return the room information?