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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 valuetype_class(self):
 """Return the valuetype class, if one is defined, or a built-in type if it isn't"""


        from ambry.valuetype import resolve_value_type

        if self.valuetype:
            return resolve_value_type(self.valuetype)

        else:
            return resolve_value_type(self.datatype)