input: Write a function to demonstrate how to return multiple values from a Python function. Use both a tuple and the 'return' statement for returning multiple values. Provide an example function and a test case to ensure the output is correct.
  def return_multiple_values():
      value1 = "ABC"
      value2 = 123
      return value1, value2
  
  value1, value2 = return_multiple_values()
  assert value1 == "ABC"
  assert value2 == 123
output: def return_multiple_values():
      value1 = "ABC"
      value2 = 123
      return value1, value2