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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def append(self, element):
 """ Append a new element to the result. :param element: The element to append :type element: overpy.Element """

        if is_valid_type(element, Element):
            self._class_collection_map[element.__class__].setdefault(element.id, element)