_createInnerGeometry () {
    // No-op
  }
TODO: FIXME: Need to expand the "key" generation used to find and get the geometries
 via getOrSet() so as to allow more specificity... i.e. we could and should
 reuse the inner geometry/icons for memory efficiency, but since right now,
 21-May-2019, radius and curveSegments are the defining inputs to createInnerGeometry()
 using the radius as the key won't uniquely identify an icon.  We need to add the icon
 name or abbreviation to the key creation.  The same as is done for getDonutGeometry()
 in nodeView.js.
   This will also open the door to actually having selectable/custom node shapes.  The
 ShapeFactory as it is now lets us have custom/selectable icons inside our standard
 node shape (circle).  Ideally, in the future without a lot more work (though the
 customizing the focused/donut graph nodes will require more work) this setup could
 be extended to create true node shape customization, i.e. square nodes instead of circles.
 I'd likely rename the current ShapeXXX to IconXXX so we could more easily distinguish what
 does what and added a shape and icon JSON field to the traffic data format.  But just like
 with the current shapes/icons we need more specificity in our keys to enable the reuse.
 Since, radius is our critical dimension and our key in order to differentiate a
 radius=16 circle versus a radius=16 (side=32) square and a storage icon versus a user icon
 versus an azure icon.
   aSqrd-eSqrd, 21-May-2019