Adding a new function to Level: find_coordinates_of_entity(). Wrote test, implementing next.
Wrote function - brute forced it.
Wrote tests for Camera except for the test for Camera.step(). Implementing functions other than Camera.step() now.
Edited Cell.get_display_images() to return the Cell's own image as priority -1. Updated tests, re-ran. Worked fine.
Got center_on working, kind of. There must be something I forgot to check because draw()'s turning out all funky but I've got to go drive my Mother to the BART station, so out of time, now.