input: Write a python function to sort a dictionary by its values.
  assert sort_dict_by_value({1: 'a', 3: 'b', 2: 'c'}) == {1: 'a', 3: 'b', 2: 'c'}
  assert sort_dict_by_value({2: 3, 1: 2, 3: 1}) == {3: 1, 1: 2, 2: 3}
  assert sort_dict_by_value({'apple': 2, 'banana': 3, 'cherry': 1}) == {'cherry': 1, 'apple': 2, 'banana': 3}
output: def sort_dict_by_value(d):
      return dict(sorted(d.items(), key=lambda item: item[1]))