input: Write a function to combine two dictionaries of similar structure together, such that the entries in the two dictionaries are merged into a single dictionary. If the same key exists in both dictionaries, the value from the second dictionary should override the value from the first dictionary. Return the merged dictionary.
  def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict
  assert merge_dict({'a':1, 'b':2, 'c':3}, {'d':4, 'e':5, 'f':6})=={'a':1, 'b':2, 'c':3, 'd':4, 'e':5, 'f':6}
  assert merge_dict({'a':1, 'b':2}, {'b':3, 'c':4})=={'a':1, 'b':3, 'c':4}
  assert merge_dict({}, {'d':4, 'e':5, 'f':6})=={'d':4, 'e':5, 'f':6}
  assert merge_dict({'a':1, 'b':2, 'c':3}, {})=={'a':1, 'b':2, 'c':3}
  assert merge_dict({}, {})=={}
output: def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict