d the tooltip width is 70, and
        // it's centered. The height of the target div is 20, and the
        // tooltip is 14px below.
        expect(contentRect.left).to.be.equal((100 - 70)/2);
        expect(contentRect.top).to.be.equal(20 + 14);

        // Also check the math, just in case.
        expect(contentRect.left).to.be.equal((divRect.width - contentRect.width)/2);
        expect(contentRect.top).to.be.equal(divRect.height + tooltip.offset);
      });
    });

    suite('a11y', function() {
   