'Use this method to get fields from the root XML tree that can appear more than once, such as \'actor\', \'genre\',
\'director\', etc. The result will be a list of values.'

def _extract_multiple_field(self, name, getter_func):

    values = [getter_func(i) for i in self._root.findall(name)]
    if (len(values) > 0):
        return values
