Since I've heard this is a bit unclear:

     testNode.childNodes[0].  // the <svg> is the first child of the testNode
              childNodes[0].  // the <g> is the first child of the <svg>
              childNodes[0];  // the <a> is the first child of the <g>
                    
I was trying to use the inline comments to make this more clear, but evidently that backfired :)