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 merged dictionary should contain all the keys and values from both dictionaries. If a key appears in both dictionaries, the value from the second dictionary should overwrite the value from the first 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({'p':7}, {})=={'p':7}
  assert merge_dict({}, {'q':8})=={'q':8}
  assert merge_dict({}, {})=={}
output: def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict