The warping operator of Gardner et al., 2017 is implemented in the function tools3d.warping_operator.warpEnvironmentMap. This allows to simulate a translation through an HDR environment map with unknown geometry by approximating it with a sphere. It can be used to relight 3D models from a different position than the camera position in the original panorama.
The function warpEnvironmentMap is documented in the source code here.
The script example_warp_operator.py shows a fun example usage, where the camera moves from the far back to the far front of the environment map. First, have a panorama image ready, e.g. pano.exr. Then, run the script with:
python tools3d/warping_operator/example_warp_operator.py --environment 'pano.exr'