def get_font(self, font):
font = {'<STR_LIT:a>': <NUM_LIT:0>, '<STR_LIT:b>': <NUM_LIT:1>}.get(font, font)<EOL>if not six.text_type(font) in self.fonts:<EOL><INDENT>raise NotSupported(<EOL>'<STR_LIT>'.format(font))<EOL><DEDENT>return font<EOL>
Return the escpos index for `font`. Makes sure that
        the requested `font` is valid.