Q12 - Echo a Response (0.5 points) We will define a function that will return a string that has been repeated a specified number of times, with a given separator. We will also want to deal with the case where the input to this function may be None. Write a function called respond_echo. This function should have the following inputs, outputs, and internal procedures: Input(s): input_string - string, or None number_of_echoes - integer spacer - string Output(s): echo_output - string, or None Procedure(s): if input_string is not None: set a variable echo_output to be input_string, repeated the number of times specified by number_of_echoes, joined by the spacer. Hint: to do so, recall what "*" does to strings otherwise (if input_string is None): set echo_output to None return echo_output Note that a simple version of this function will end up appending the spacer to the end of the list as well. For our purposes here, implement that simple version.