@abc.abstractmethod<EOL><INDENT>def get_femtoseconds(self):<DEDENT>
return<EOL>
Gets the number of femtoseconds of the picosecond 0-999.

        A femtosecond is one quadrillionth of a second.

        :return: the femtoseconds of the picosecond
        :rtype: ``cardinal``


        *compliance: mandatory -- This method must be implemented.*