参数 描述 track The track number to get the animation set name of.
A single skeletal animation sprite can have various animation sets, and these sets can be assigned different tracks so that you can "mix and match" animation sets. This function will return the name of the animation set currently used by the given track number (as set by the function skeleton_animation_set_ext).重要！该函数在试用版（Trial License）产品中不可用。
if skeleton_animation_get_ext(1) != "bodyfight"
The above code will change the animation set being used by track 1 to "bodyfight" if it is not already.