def _get_abbreviations(input_string, output_length=0):
        """ Generates abbreviations for input_string

        :param input_string: str, name of object
        :param output_length: int, optional specific length of abbreviations, default is off
        :return: list(str), list of all combinations that include the first letter (possible abbreviations)
        """
        for i, j in itertools.combinations(range(len(input_string[1:]) + 1), 2):
            abbr = input_string[0] + input_string[1:][i:j]
            if len(abbr) >= output_length:
                yield abbr
            elif output_length == 0:
                yield abbr
        # Have to add the solitary letter as well
        if not output_length or output_length == 1:
            yield input_string[0]
Generates abbreviations for input_string

        :param input_string: str, name of object
        :param output_length: int, optional specific length of abbreviations, default is off
        :return: list(str), list of all combinations that include the first letter (possible abbreviations)