server-tools/base_import_odoo/demo/ir_attachment.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <record id="attachment_demo" model="ir.attachment">
        <field name="name">Demo attachment</field>
        <field name="res_model">res.users</field>
        <field name="res_id" ref="base.user_demo" />
        <field name="datas">aGVsbG8gd29ybGQK</field>
    </record>
</odoo>