I fixed everything you said  (the callback and this jshint) but there's a last one thing in the jshint([L113:C40] W074: This function's cyclomatic complexity is too high. (9)
C2SStream.prototype.onStanza = function(stanza) {
)

it's just when I add an OR condition to the IF or if I add another elseif instead of the OR. How can i solve this?