python 3, to_array (in-sorted)

to_array: This function takes a dictionary that maps keys to lists of numbers and returns a numpy matrix containing the numbers in the lists. Traverse the keys of the dictionary in sorted order. For example, if the dictionary is: {'a': [1, 2, 3], 'c': [7, 8, 9], 'b': [4, 5, 6] } Then your function should return the array: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]