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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 _validate_columns(self):
 """Validate the options in the styles"""

        geom_cols = {'the_geom', 'the_geom_webmercator', }
        col_overlap = set(self.style_cols) & geom_cols
        if col_overlap:
            raise ValueError('Style columns cannot be geometry '
                             'columns. `{col}` was chosen.'.format(
                                 col=','.join(col_overlap)))