@cached_property<EOL><INDENT>def extensions(self):<DEDENT>
_tmp_extensions = self.mimes.encodings_map.keys() +self.mimes.suffix_map.keys() +self.mimes.types_map[<NUM_LIT:1>].keys() +cfg['<STR_LIT>']<EOL>extensions = []<EOL>for ext in _tmp_extensions:<EOL><INDENT>if ext.startswith('<STR_LIT:.>'):<EOL><INDENT>extensions.append(ext)<EOL><DEDENT>else:<EOL><INDENT>extensions.append('<STR_LIT:.>' + ext)<EOL><DEDENT><DEDENT>extensions.sort()<EOL>extensions.reverse()<EOL>extensions = set([ext.lower() for ext in extensions])<EOL>extensions = '<STR_LIT:\\>' + '<STR_LIT>'.join(extensions) + '<STR_LIT:$>'<EOL>extensions = extensions.replace('<STR_LIT:+>', '<STR_LIT>')<EOL>return re.compile(extensions, re.I)<EOL>
Generate the regular expression to match all the known extensions.

@return: the regular expression.
@rtype: regular expression object