Document how to convert coordinate from ECI to LLA

I’ve been reading over the documentation and I can’t quite figure out how to leverage skyfield to convert a coordinate from earth-centered inertial (ECI, given as x, y, z) to LLA (lat, long, altitude). Consider the following example

from datetime import datetime, timedelta
obs_time = datetime(2000, 1, 1) + timedelta(seconds=240)   # observe at 2000-01-01 00:04:00

# Given x, y, z coordinates in ECI [meters]
eci = (2183457.758387, 1924098.065987, 5898755.881731)

# What I would like to do
lat, lon, alt = eci_to_lla(eci, obs_time)

# expected output should be somewhere over eastern europe
# lat = 63.7398
# lon = 40.3853
# alt = 199473.0 

Is there a class in skyfield.positionlib that I can use to accomplish this calculation?