Picks the random item based on its weight. The items with higher weight will be picked more often (with a higher probability).

For example:

• items = ['banana', 'orange', 'apple']
• weights = [0, 0.2, 0.8]
• weightedRandom(items, weights) in 80% of cases will return 'apple', in 20% of cases will return 'orange' and it will never return 'banana' (because probability of picking the banana is 0%)