For both parts below, be careful to make sure that you don't change the values of the original list being passed to the function: 

• Write a function, has_duplicate(input_list), that accepts a list and returns True if the list has a duplicate item and False if it does not. 
• Write a function, remove_duplicate(input_list), that accepts a list and returns the list, in order, keeping only the first instance of any duplicated values.

Then, write a function, invert_dict(input_dictionary), that accepts a dictionary whose keys and values are both of immutable types and returns a dictionary whose keys are the values of the input dictionary and whose values are ordered lists of keys that share that value.