code: def get_first_child_of_type(self, klass):
          
          matches = self.find_children(lambda c: isinstance(c, klass))
          if len(matches):
              return matches[0]
          else:
              return None
docs: ! @brief Breadth-first search for a child of the given class.
          @param self
          @param klass The class type to search for. The first child at any depth that is an instance
              of this class or a subclass thereof will be returned. Matching children at more shallow
              nodes will take precedence over deeper nodes.
          @returns Either a node object or None.