Add a new key/value pair. Key in column 9 (FORMAT)
        and value in column 10. If key already exists, then updates
        the value to the new given value

def set_format_key_value(self, key, value):
        '''Add a new key/value pair. Key in column 9 (FORMAT)
        and value in column 10. If key already exists, then updates
        the value to the new given value'''
        if self.format_keys is None:
            self.format_keys = []
            self.FORMAT = {}
        if key not in self.FORMAT:
            self.format_keys.append(key)
        self.FORMAT[key] = value