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. The function should take two dictionaries as input and return a single 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({'x':10, 'y':20}, {'y':25, 'z':30})=={'x':10, 'y':25, 'z':30}
  assert merge_dict({}, {'a':1, 'b':2})=={'a':1, 'b':2}
  assert merge_dict({'a':1}, {'a':2})=={'a':2}
  assert merge_dict({}, {})=={}
output: def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict