[jQuery] Question on : syntax

[jQuery] Question on : syntax


I have yet another syntax question.
I know that : can be used for specifying things like filters, but what
does it do in this case:
$jc.fn.extend({
setup: function() {
this.first = null;
this.last = null;
this.prevFirst = null;
this.prevLast = null;
this.animating = false;
this.timer = null;
this.tail = null;
this.inTail = false;
if (this.locked)
return;
this.list.css(this.lt, this.pos(this.options.offset) +
'px');
...rest of code here
},
so what is the syntax setup: an attribute?