def set_style(self, style):
        """Set pygments syntax highlighting style."""
        if style == "none":
            self.style = None
        elif prompt_toolkit is None:
            raise CoconutException("syntax highlighting is not supported on this Python version")
        elif style == "list":
            print("Coconut Styles: none, " + ", ".join(pygments.styles.get_all_styles()))
            sys.exit(0)
        elif style in pygments.styles.get_all_styles():
            self.style = style
        else:
            raise CoconutException("unrecognized pygments style", style, extra="use '--style list' to show all valid styles")
Set pygments syntax highlighting style.