The bounds of each frame (frameBounds), or null when not published
The key of the symbol in the published lib (used as is, including
non-ASCII names). Symbols that are not in lib (a bare createjs.MovieClip
created inside a constructor, or a class the content never registered)
get an id starting with #.
The kind of symbol
The bounds published on the symbol (nominalBounds), or null
What it shows
A Sprite symbol (a frame of a sprite sheet).