Returns *string* with all instances of '<', '>', and '&' converted into
        HTML entities.

def escape(self, string):
        """
        Returns *string* with all instances of '<', '>', and '&' converted into
        HTML entities.
        """
        html_entities = {"&": "&amp;", '<': '&lt;', '>': '&gt;'}
        return HTML("".join(html_entities.get(c, c) for c in string))