def apply_mirroring(storage, debug):
<EOL>for _ch in storage['<STR_LIT>']:<EOL><INDENT>unichar = _ch['<STR_LIT>']<EOL>if mirrored(unichar) and_embedding_direction(_ch['<STR_LIT>']) == '<STR_LIT:R>':<EOL><INDENT>_ch['<STR_LIT>'] = MIRRORED.get(unichar, unichar)<EOL><DEDENT><DEDENT>if debug:<EOL><INDENT>debug_storage(storage)<EOL><DEDENT>
Applies L4: mirroring

    See: http://unicode.org/reports/tr9/#L4