DomainOf the specified url.

HTTPGet initiates HTTP get request and returns its response.

HTTPGetResponse initiates HTTP get request and returns its response.

Now returns date time in the format of "2006-01-02 15:04:05".

PickGlobalProxy randomly chooses a global proxy from database.

PickProxy randomly chooses a proxy from database.

PickUserAgent picks a user agent string from the pool randomly.if the pool is not populated, it will trigger the initialization processto fetch user agent lists from remote server.

Rot13 Cipher obscures the characters in a string by rotating characters13 places in the alphabet.

UpdateProxyScore for the specified proxy.

UpdateProxyScoreGlobal updates globa score for the specified proxy.

ValidateProxy checks the status of remote listening port, and further checks if it's a valid proxy server.

DateTimeFormat unified in the program.