Write a function long_high_word(wordlist) that takes a non-empty list of words wordlist (each of which is a string), and returns the word which is longest, and in the instance of multiple words having that length, is highest among them, based on Unicode sort order. For example:

>>> long_high_word(['a', 'cat', 'sat']) 

'sat' 

>>> long_high_word(['saturation', 'of', 'colour']) 

'saturation' 

>>> long_high_word(['samIam']) 

'samIam'