'Update a view section. The view section may embed fields to write
:param str xpath: valid xpath to the tag to replace'

@api.multi
def save(self, value, xpath=None):

    arch_section = html.fromstring(value, parser=html.HTMLParser(encoding='utf-8'))
    if (xpath is None):
        self.save_embedded_field(arch_section)
        return
    for el in self.extract_embedded_fields(arch_section):
        self.save_embedded_field(el)
        el.getparent().replace(el, self.to_field_ref(el))
    for view in self:
        arch = view.replace_arch_section(xpath, arch_section)
        view.write({'arch': view._pretty_arch(arch)})
    self.sudo().mapped('model_data_id').write({'noupdate': True})
