Function boolean_mask

Apply boolean mask to tensor. Numpy equivalent is `tensor[mask]`. ```python # 1-D example tensor = [0, 1, 2, 3] mask = np.array([True, False, True, False]) boolean_mask(tensor, mask) # [0, 2] ``` In general, `0 < dim(mask) = K <= dim(tensor)`, and `mask`'s shape must match the fi

(tensor, mask, name="boolean_mask")