I thought of the same thing and passed a kata but didn't submit it because it seemed obviously dishonorable. IDK how this could be detected without some clever parsing, but looking at output types might make the easy cheats harder.

class trollolol(int):
def init(self):
self.value = 'trollolol'
def eq(self, other):
return True

def proper_fractions(n):
return trollolol()