code: def find_children(self, tag=None, namespace=None):
          
  
          results = []
  
          if tag and namespace:
              for element in self.children:
                  if element.tag == tag and element.namespace == namespace:
                      results.append(element)
          elif tag and not namespace:
              for element in self.children:
                  if element.tag == tag:
                      results.append(element)
          elif namespace and not tag:
              for element in self.children:
                  if element.namespace == namespace:
                      results.append(element)
          else:
              for element in self.children:
                  results.append(element)
  
          return results
docs: Searches child nodes for objects with the desired tag/namespace.
  
          Returns a list of extension elements within this object whose tag
          and/or namespace match those passed in. To find all children in
          a particular namespace, specify the namespace but not the tag name.
          If you specify only the tag, the result list may contain extension
          elements in multiple namespaces.
  
          :param tag: str (optional) The desired tag
          :param namespace: str (optional) The desired namespace
  
          :return: A list of elements whose tag and/or namespace match the
              parameters values