'Header-row layout: same as default, but non-static (i.e. hiding
if there are no visible read-rows, because edit-rows have their
own labels)'

def headers(self, data, readonly=False):

    headers = super(S3SQLVerticalSubFormLayout, self).headers
    header_row = headers(data, readonly=readonly)
    element = header_row.element('tr')
    if hasattr(element, 'remove_class'):
        element.remove_class('static')
    return header_row
