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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 convert(self, targetunits):
 """Set new user unit, for wavelength only. This effectively converts the spectrum wavelength to given unit. Note that actual data are always kept in internal unit (Angstrom), and only converted to user unit by :meth:`GetWaveSet` during actual computation. User unit is stored in ``self.waveunits``. Throughput is unitless and cannot be converted. Parameters targetunits : str New unit name, as accepted by `~pysynphot.units.Units`. """

        nunits = units.Units(targetunits)
        self.waveunits = nunits