Fast MIMIC Fails TSPOpt

[gnodabb]

When running TSPOpt problem with custom distance. MIMIC fails only when fast_mimic=True.

Code that works:

best_state, best_fitness, fit_curve = mlrose.mimic(problem_cust, max_attempts=100, max_iters=1000, random_state=42,
                                                       curve=True)

Code that fails:

best_state, best_fitness, fit_curve = mlrose.mimic(problem_cust, max_attempts=100, max_iters=1000, random_state=42,
                                                   fast_mimic=True, curve=True)

It is specifically failing in opt_probs.py on line 1010. The issue is that remaining is empty and it's trying to pull a random choice from an empty array.