def METHOD_NAME(self, key):
    """Process key."""
    if key.startswith(('"', "'")):
        value = (None, html.unescape(ESCAPE_RE.sub(r'\1', key[1:-1])).strip())
    else:
        norm_key = self.normalize(key)
        canonical_key = self.aliases.get(norm_key, norm_key)
        name = self.map.get(canonical_key, None)
        value = (canonical_key, name) if name else None
    return value