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.
  
  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({'x':7, 'y':8}, {'x':9, 'z':10}) == {'x': 9, 'y': 8, 'z': 10}
  assert merge_dict({}, {'a':1, 'b':2}) == {'a': 1, 'b': 2}
  assert merge_dict({'a':1, 'b':2}, {}) == {'a': 1, 'b': 2}
output: def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict