How to get points or number of points inside a Tsdf voxel

[vovaekb]

I need to calculate a points density in point cloud using some voxel-based representation like Octree. I consider voxblox as a good solution for creating such a representation of point cloud.
I observed that voxblox uses Tsdf / Esdf voxels. Is there a way to get the number of points from the original point cloud falling inside a single Tsdf voxel or points itself?