input: Write a function that takes two dictionaries as input and merges them into a single dictionary. The function should return the merged dictionary. If both dictionaries have the same key, 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':1, 'q':2}, {}) == {'p':1, 'q':2}
  assert merge_dict({}, {'r':3, 's':4}) == {'r':3, 's':4}
  assert merge_dict({}, {}) == {}
output: def merge_dict(dict_a, dict_b):
      merged_dict = {**dict_a, **dict_b}
      return merged_dict