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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 _get_column(cls, name):
 """ Based on cqlengine.models.BaseModel._get_column. But to work with 'pk' """

        if name == 'pk':
            return cls._meta.get_field(cls._meta.pk.name)
        return cls._columns[name]