How to inherit this report and set the landscape orientation in my module?
<report 
    string="Purchase Order" 
    id="action_report_purchase_order" 
    model="purchase.order" 
    report_type="qweb-pdf"
    name="purchase.report_purchaseorder" 
    file="purchase.report_purchaseorder"
    print_report_name="
        (object.state in ('draft', 'sent') and 'Request for Quotation - %s' % (object.name) or
        'Purchase Order - %s' % (object.name))"
/>