code: function centeringProperties(_ref3) {
      var oDim = _ref3.oDim,
          wDim = _ref3.wDim,
          tPos = _ref3.tPos,
          tDim = _ref3.tDim;
      var center = Math.round(tPos + tDim / 2);
      var leftOffset = oDim / 2 - center;
      var rightOffset = center + oDim / 2 - wDim;
      return {
        center: center,
        leftOffset: leftOffset,
        rightOffset: rightOffset
      };
    }
docs: computes offsets (off screen overlap) of popover when trying to align it to the center