TA.Timeline
TA.Timeline objects glue all together and are the core of what TA actually is.
A Timeline actually consists of two parts: the TA.Timeline itself and a TA.TimelineDescriber that helps you write the Timeline.
TA.TimelineDescriber (JSDoc)
To get a describer call timeline.getDescriber(); on a TA.Timeline object. Keep in mind that each Timeline has its own Describer.