Tuple for vectorized indexing.
All elements should be slice or N-dimensional np.ndarray objects with an integer dtype and the same number of dimensions. Indexing follows proposed rules for np.ndarray.vindex, which matches NumPy’s advanced indexing rules (including broadcasting) except sliced axes are always moved to the end: https://github.com/numpy/numpy/pull/6256
Initialize self. See help(type(self)) for accurate signature.