Description: You get an array of arrays. If you sort the arrays by their length, you will see, that their length-values are consecutive. But one array is missing! You have to write a method, that return the length of the missing array. Example: [[1, 2], [4, 5, 1, 1], [1], [5, 6, 7, 8, 9]] --> 3 If the array of arrays is null/nil or empty, the method should return 0. When an array in the array is..