Demo example:

<record id="user_demo" model="res.users">

<field name="partner_id" ref="base.partner_demo"/>

<field name="login">demo</field>

<field name="password">demo</field>

<field name="signature">--

Mr Demo</field>

<field name="company_id" ref="base.main_company"/>

<field name="groups_id" eval="[(6,0,[ref('base.group_user'), ref('base.group_partner_manager')])]"/>

<field name="image" type="base64" file="base/static/img/user_demo-image.jpg"/>

</record>