@davidfowl , yes, in jquery.signalR.transports.common.js:
https://github.com/SignalR/SignalR/blob/release/src/Microsoft.AspNet.SignalR.Client.JS/jquery.signalR.transports.common.js#L463
https://github.com/SignalR/SignalR/blob/release/src/Microsoft.AspNet.SignalR.Client.JS/jquery.signalR.transports.common.js#L470