docs: def process_nested_tags(self, node, tag = ''):
          """
          Process child tags.
  
          @param node: Current node being parsed.
          @type node: xml.etree.Element
  
          @raise ParseError: Raised when an unexpected nested tag is found.
          """
          ##print("---------Processing: %s, %s"%(node.tag,tag))
  
          if tag == '':
              t = node.ltag
          else:
              t = tag.lower()
          
          for child in node.children:
              self.xml_node_stack = [child] + self.xml_node_stack
  
              ctagl = child.ltag
  
              if ctagl in self.tag_parse_table and ctagl in self.valid_children[t]:
                  #print("Processing known type: %s"%ctagl)
                  self.tag_parse_table[ctagl](child)
              else:
                  #print("Processing unknown type: %s"%ctagl)
                  self.parse_component_by_typename(child, child.tag)
  
              self.xml_node_stack = self.xml_node_stack[1:]