<?xml version="1.0"?>
<data><field name="tz" position="attributes">
                    <attribute name="required">1</attribute>
                </field>
                <field name="tz" position="after">
                    <field name="is_system" invisible="1"/>
                </field>
                <xpath expr="//button[@name='44']" position="attributes">
                    <attribute name="invisible">not is_system</attribute>
                </xpath>
            </data>