code: def _is_ns_in_ancestor(self, node, name, value):
          
          curr_node = self.get_node_parent(node)
          while curr_node.__class__ == etree._Element:
              if (hasattr(curr_node, 'nsmap')
                      and curr_node.nsmap.get(name) == value):
                  return True
              for n, v in curr_node.attrib.items():
                  if v == value and '{%s}' % nodes.Node.XMLNS_URI in n:
                      return True
              curr_node = self.get_node_parent(curr_node)
          return False
docs: Return True if the given namespace name/value is defined in an
          ancestor of the given node, meaning that the given node need not
          have its own attributes to apply that namespacing.