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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 localopt(self, forcefield='mmff94', steps=500):
 """ A wrapper to pybel's localopt method to optimize a Molecule. Args: forcefield: Default is mmff94. Options are 'gaff', 'ghemical', 'mmff94', 'mmff94s', and 'uff'. steps: Default is 500. """

        pbmol = pb.Molecule(self._obmol)
        pbmol.localopt(forcefield=forcefield, steps=steps)
        self._obmol = pbmol.OBMol