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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 add_row(self, list_or_dict, key=None):
 """ Adds a list or dict as a row in the FVM data structure :param str key: key used when rows is a dict rather than an array :param list_or_dict: a feature list or dict """

        if isinstance(list_or_dict, list):
            self._add_list_row(list_or_dict, key)
        else:
            self._add_dict_row(list_or_dict, key)