def add_search_character(self, char: Keys) -> None:
        """Adds a character to the search filter"""
        if char == Keys.Backspace:
            self.remove_search_character()
        else:
            if self.search_filter is None:
                self.search_filter = str(char)
            else:
                self.search_filter += str(char)

        # Make sure that the selection is in the bounds of the filtered list
        self.pointed_at = 0
Adds a character to the search filter
questionary/prompts/common.py