code: def convert_tree(self, element1, element2=None):
          '''convert_tree
  
          High-level api: Convert cxml tree to an internal schema tree. This
          method is recursive.
  
          Parameters
          ----------
  
          element1 : `Element`
              The node to be converted.
  
          element2 : `Element`
              A new node being constructed.
  
          Returns
          -------
  
          Element
              This is element2 after convertion.
          '''
  
          if element2 is None:
              attributes = deepcopy(element1.attrib)
              tag = attributes['name']
              del attributes['name']
              element2 = etree.Element(tag, attributes)
          for e1 in element1.findall('node'):
              attributes = deepcopy(e1.attrib)
              tag = self.prefix_to_url(attributes['name'])
              del attributes['name']
              e2 = etree.SubElement(element2, tag, attributes)
              self.convert_tree(e1, e2)
          return elementf convert_tree(self, element1, element2=None):
          '''convert_tree
  
          High-level api: Convert cxml tree to an internal schema tree. This
          method is recursive.
  
          Parameters
          ----------
  
          element1 : `Element`
              The node to be converted.
  
          element2 : `Element`
              A new node being constructed.
  
          Returns
          -------
  
          Element
              This is element2 after convertion.
          '''
  
          if element2 is None:
              attributes = deepcopy(element1.attrib)
              tag = attributes['name']
              del attributes['name']
              element2 = etree.Element(tag, attributes)
          for e1 in element1.findall('node'):
              attributes = deepcopy(e1.attrib)
              tag = self.prefix_to_url(attributes['name'])
              del attributes['name']
              e2 = etree.SubElement(element2, tag, attributes)
              self.convert_tree(e1, e2)
          return element2
docs: convert_tree
  
          High-level api: Convert cxml tree to an internal schema tree. This
          method is recursive.
  
          Parameters
          ----------
  
          element1 : `Element`
              The node to be converted.
  
          element2 : `Element`
              A new node being constructed.
  
          Returns
          -------
  
          Element
              This is element2 after convertion.