fails:Net::FTP#help writes the HELP command to the server
fails:Net::FTP#help returns the server's response
fails:Net::FTP#help writes the HELP command with an optional parameter to the socket
fails:Net::FTP#help does not raise any error when the response code is 211
fails:Net::FTP#help does not raise any error when the response code is 214
fails:Net::FTP#help raises a Net::FTPPermError when the response code is 500
fails:Net::FTP#help raises a Net::FTPPermError when the response code is 501
fails:Net::FTP#help raises a Net::FTPPermError when the response code is 502
fails:Net::FTP#help raises a Net::FTPTempError when the response code is 421
