input: Write a function to count the occurrences of each item in a given dictionary. If the input dictionary is empty then return an empty dictionary.
  assert item_counts({"apples": 5, "oranges": 6, "bananas": 7})=={"apples": 5, "oranges": 6, "bananas": 7}
  assert item_counts({})=={}
output: def item_counts(d):
      return d