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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 ndim(self):
 """If given FeatureType stores a dictionary of numpy.ndarrays it returns dimensions of such arrays."""

        if self.is_raster():
            return {
                FeatureType.DATA: 4,
                FeatureType.MASK: 4,
                FeatureType.SCALAR: 2,
                FeatureType.LABEL: 2,
                FeatureType.DATA_TIMELESS: 3,
                FeatureType.MASK_TIMELESS: 3,
                FeatureType.SCALAR_TIMELESS: 1,
                FeatureType.LABEL_TIMELESS: 1
            }[self]
        return None