export declare type Charset = 'ASCII' | 'cp1252' | 'GB18030' | 'GB2312' | 'GBK' | 'ISO-8859-1' | 'ISO-8859' | 'US-ASCII' | 'UTF-16-LE' | 'UTF-16' | 'UTF-32-BE' | 'UTF-32' | 'UTF-8' | 'utf8';