Gets or sets a value that indicates whether to preserve the aspect ratio when moving a corner thumb.
Object.defineProperty(AnnEditDesigner.prototype, 'maintainAspectRatio',get: function(),set: function(value))
maintainAspectRatio: boolean; true to preserve the aspect ratio when moving a corner thumb; otherwise, it is false. The default value is true.
When selecting an AnnRectangleObject, or any annotation object that derives from an AnnRectangleObject, eight thumbs appear. If MaintainAspectRatio is true (default), dragging one of the four corner thumbs changes the size of the annotation object while maintaining its aspect ratio. If false, the aspect ratio won't be preserved.
