The supersets API should return the "list of items that include the specified
item".
I ran it using torso 973pb0428 in color_id=11 (black) and it returned 19 items:
7 sets and 12 minifigs. But it is also part of one part - Torso Assembly 973pb0428c01
Can someone look into this to make sure the API returns everything that the webpage
does? It's important not to guess because there are sometimes multiple torso
assemblies that use a given torso and I don't want to start guessing because
there's no guarantee that they will always be in the format 973pbxxxc##
USA, Georgia
