<main_elt xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="gmlas_remove_unused_layers_and_fields.xsd">
    <used1>foo</used1>
    <used2>bar</used2>
    <nillable xsi:nil="true" nilReason="unknown"/>
</main_elt>
