         # File lib/em/protocols/saslauth.rb, line 139
    139:       def validate? username, psw, sysname=nil, realm=nil
    140:
    141:         str = [username, psw, sysname, realm].map {|m|
    142:           [(m || "").length, (m || "")]
    143:         }.flatten.pack( "nA*" * 4 )
    144:         send_data str
    145:
    146:         d = EM::DefaultDeferrable.new
    147:         @queries.unshift d
    148:         d
    149:       end