EntityRef
EntityRef =
ArcCurveRef|CurveRef|DrawingElementRef|ImageEntityRef|MaterialRef|SceneRef|TagRef|TagFolderRef|TextureRef|UnknownEntityRef|VertexRef|StyleRef
An entity is the root of the object hierarchy in SketchUp, representing physical geometry and other meta types.
NOTE: This reference is only valid in the operation that constructed it
SketchupOperation#entity