Hello, I tried to expand base.xml template. Example is:

<?xml version="1.0" encoding="UTF-8"?>
<templates xml:space='preserve'>
    <t t-extend="FormView.buttons">
        <t t-if="widget.fields_view.state !== 'done'">
        <div class="o_form_buttons_view">
            <button t-if="widget.is_action_enabled('create')"
                    type="button" class="oe_form_button_create btn btn-default btn-sm"
                    accesskey="C">
                Create
            </button>
        </div>
        </t>
    </t>
</templates>

To manifest (__openerp__.py) added "base" to dependences and:ded base to dependencies:

'qweb' : [
        "static/src/xml/base.xml",
    ],

But nothing happens, what's wrong?