_.transform(object, [iteratee=_.identity], [accumulator])
_.transform([2, 3, 4], function(result, n) { result.push(n*=n); returnn%2==0; }, []); // => [4, 9]_.transform({ 'a': 1, 'b': 2, 'c': 1 }, function(result, value, key) { (result[value] || (result[value] = [])).push(key); }, {}); // => { '1': ['a', 'c'], '2': ['b'] }
