setTransform is an advanced method for directly manipulating the transformation matrix when drawing to this image. It is designed for advanced users, and not for beginners. For most cases, 'rotate', 'scale' and 'translate' are the best methods to use.
The method is for setting a new matrix onto this image, which is used when drawing onto this Image.
It replaces the current matrix, and can be undone by calling the 'undoTransform' or 'clearTransforms' methods.