Function nearest_k_spatial_tensor 

pub fn nearest_k_spatial_tensor<I: ChunkedNearestNeighborIndex>(
    index: &I,
    x: &[f32],
    y: &[f32],
    z: &[f32],
    tensor: &SpatialTensor<'_>,
    k: usize,
    out: &mut Vec<(usize, Neighbor)>,
)

Runs k-NN search for every chunk in a SpatialTensor, appending tagged neighbors.