A Mystery Tree at Hidden Lake

I have a mystery tree in a walled-in corner just outside my garage door at Hidden Lake.  My local nursery couldn't tell what it is from just a leaf sample.  Here is a full frontal picture of my tree.

It is about six feet tall and can grow taller, I think.  I looks to be more than six feet across.  The leaves haven't begun to turn color and I can't say whether they will do that.

The trunk appears to peel, reminding me of birch.  Color is copper brown.  At a height of three feet, I appears to have been purposely "topped" to force all its branches to emerge from its head.  Growth is dense.

Leaves are dark green, mounted in pairs, with buds at the leaf notches.  Veins radiate from the base of the leaf.  Edges are smooth, not hacksaw.  Form is rounded, generally coming to a point.

Note the buds at the leaf notches.

Growth habit appears to provide for substantial expansion each year.  If so, this tree has no business in its current location.  If you know what this is, please drop a comment.