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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 filter_infinity(self):
 """Filter infinite distances from ``PointCloud.``"""

        mask = self.coordinates[:, 2] > self.coordinates[:, 2].min()
        coords = self.coordinates[mask]
        colors = self.colors[mask]
        return PointCloud(coords, colors)