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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 _getZoomLevelRange(self, resolution, unit='meters'):
        "Return lower and higher zoom level given a resolution"
        assert unit in ('meters', 'degrees')
        if unit == 'meters' and self.unit == 'degrees':
            resolution = resolution / self.metersPerUnit
        elif unit == 'degrees' and self.unit == 'meters':
            resolution = resolution * EPSG4326_METERS_PER_UNIT
        lo = 0
        hi = len(self.RESOLUTIONS)
        while lo < hi:
            mid = (lo + hi) // 2
            if resolution > self.RESOLUTIONS[mid]:
                hi = mid
            else:
                lo = mid + 1
        return lo, hi