input: Write a function to sort a dictionary by its values in descending order.
  assert sortByValue({"A": 30, "B": 40, "C": 20}) == {'B': 40, 'A': 30, 'C': 20}
  assert sortByValue({"apple": 2, "banana": 5, "cherry": 3}) == {'banana': 5, 'cherry': 3, 'apple': 2}
  assert sortByValue({"x": 1, "y": 1, "z": 1}) == {'x': 1, 'y': 1, 'z': 1}
output: def sortByValue(d):
      return dict(sorted(d.items(), key=lambda item: item[1], reverse=True))