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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 from_cfunits(cls, units) -> 'Date': """Return a |Date| object representing the reference date of the given `units` string agreeing with the NetCDF-CF conventions. The following example string is taken from the `Time Coordinate`_ chapter of the NetCDF-CF conventions documentation (modified). Note that the first entry (the unit) is ignored: Date('1992-10-08 22:15:42') Date('1992-10-08 15:15:00') Date('1992-10-08 07:00:00') Date('1992-10-08 00:00:00') Without modification, when "0" is included as the decimal fractions of a second, the example string from `Time Coordinate`_ can also be passed. However, fractions different from "0" result in an error: Date('1992-10-08 15:15:42') Date('1992-10-08 15:15:42') Date('1992-10-08 22:15:42') Date('1992-10-08 22:15:42') Traceback (most recent call last):
 ValueError: While trying to parse the date of the NetCDF-CF "units" \ string `seconds since 1992-10-8 15:15:42.005 -6:00`, the following error \ occurred: No other decimal fraction of a second than "0" allowed. """

        try:
            string = units[units.find('since')+6:]
            idx = string.find('.')
            if idx != -1:
                jdx = None
                for jdx, char in enumerate(string[idx+1:]):
                    if not char.isnumeric():
                        break
                    if char != '0':
                        raise ValueError(
                            'No other decimal fraction of a second '
                            'than "0" allowed.')
                else:
                    if jdx is None:
                        jdx = idx+1
                    else:
                        jdx += 1
                string = f'{string[:idx]}{string[idx+jdx+1:]}'
            return cls(string)
        except BaseException:
            objecttools.augment_excmessage(
                f'While trying to parse the date of the NetCDF-CF "units" '
                f'string `{units}`')